Halacha

הלכה א
כָּל כֹּהֲנִים בַּזְּמַן הַזֶּה בַּחֲזָקָה הֵם כֹּהֲנִים וְאֵין אוֹכְלִין אֶלָּא בְּקָדְשֵׁי הַגְּבוּל. וְהוּא שֶׁתִּהְיֶה תְּרוּמָה שֶׁל דִּבְרֵיהֶם. אֲבָל תְּרוּמָה שֶׁל תּוֹרָה וְחַלָּה שֶׁל תּוֹרָה אֵין אוֹכֵל אוֹתָהּ אֶלָּא כֹּהֵן מְיֻחָס:
כסף משנה
1.
[The status of] all of the priests of the present era1When the priests do not serve in the Temple and there is no Sanhedrin to verify their lineage. is accepted on the basis of a prevailing assumption.2I.e., they are regarded as priests by people at large even though there is no definite proof of their lineage. They may only eat sacred food that is eaten [within] the boundaries [of Eretz Yisrael],3I.e., in contrast to sacrificial meat which may be eaten only in the Temple courtyard or within the city of Jerusalem depending on the type of sacrifice involved. provided it is terumah mandated by virtue of Rabbinic decree [alone].4As explained in Halachah 3, in the present age, the mitzvah of terumah has the status of a Rabbinic commandment. As reflected by the commentaries to Hilchot Terumah 2:1, according to the Rambam, Scriptural Law requires us to separate terumah from all types of produce usually eaten by humans. The mitzvah does not apply only to the grain, grapes, and olives singled out by Deuteronomy 18:4. [Even] terumah mandated by Scriptural Law and challah mandated by Scriptural Law, by contrast, may be eaten only by a priest whose lineage is established.

הלכה ב
אֵי זֶהוּ כֹּהֵן מְיֻחָס כָּל שֶׁהֵעִידוּ לוֹ שְׁנֵי עֵדִים שֶׁהוּא כֹּהֵן בֶּן פְּלוֹנִי הַכֹּהֵן וּפְלוֹנִי בֶּן פְּלוֹנִי הַכֹּהֵן עַד אִישׁ שֶׁאֵינוֹ צָרִיךְ בְּדִיקָה וְהוּא הַכֹּהֵן שֶׁשִּׁמֵּשׁ עַל גַּבֵּי הַמִּזְבֵּחַ. שֶׁאִלּוּ לֹא בָּדְקוּ בֵּית דִּין הַגָּדוֹל אַחֲרָיו לֹא הָיוּ מְנִיחִין אוֹתוֹ לַעֲבֹד. לְפִיכָךְ אֵין בּוֹדְקִין מֵהַמִּזְבֵּחַ וָמַעְלָה וְלֹא מִן הַסַּנְהֶדְרִין וָמַעְלָה. שֶׁאֵין מְמַנִּין בַּסַּנְהֶדְרִין אֶלָּא כֹּהֲנִים לְוִיִּים וְיִשְׂרְאֵלִים מְיֻחָסִין:
כסף משנה
2.
What is meant by a priest whose lineage is established? Anyone concerning whom two witnesses5Note the Maggid Mishneh who elaborates, explaining that although generally, the testimony of one witness is sufficient with regard to issues involving Scriptural prohibitions, an exception is made with regard to terumah. testify that he is a priest, the son of so-and-so the priest, and the descendant of so-and-so the priest, extending back until we reach a person whose lineage need not be checked, i.e., a priest who served at the altar. [Such a person's lineage need not be verified, because] were the High Court not to have made investigations about him, they would not have allowed him to perform service [in the Temple].6See the conclusion of the tractate of Middot and Hilchot Bi'at HaMikdash 6:11, which describes the manner in which the lineage of the priests was checked.
Accordingly, we do not investigate the lineage of anyone who served at the altar or who served on the Sanhedrin. For only priests, Levites, and Israelites of acceptable lineage are appointed to the Sanhedrin.7See Hilchot Sanhedrin 2:1.

הלכה ג
חַלָּה בַּזְּמַן הַזֶּה וַאֲפִלּוּ בְּאֶרֶץ יִשְׂרָאֵל אֵינָהּ שֶׁל תּוֹרָה שֶׁנֶּאֱמַר (במדבר טו יח) "בְּבֹאֲכֶם אֶל הָאָרֶץ" בִּיאַת כֻּלְּכֶם וְלֹא בִּיאַת מִקְצַתְכֶם. וּכְשֶׁעָלוּ בִּימֵי עֶזְרָא לֹא עָלוּ כֻּלָּם. וְכֵן תְּרוּמָה בַּזְּמַן הַזֶּה שֶׁל דִּבְרֵי סוֹפְרִים וּלְפִיכָךְ אוֹכְלִים אוֹתָהּ הַכֹּהֲנִים שֶׁבִּזְמַנֵּינוּ שֶׁהֵן בַּחֲזָקָה:
כסף משנה
3.
In the present era, even in Eretz Yisrael,8As the Rambam explains in Hilchot Bikkurim 5:5,7, in the Biblical era, there was a distinction between the mitzvah of challah as observed in Eretz Yisrael and as observed in the Diaspora. For according to Scriptural Law, the mitzvah applies only in Eretz Yisrael. challah does not have the status of a Scriptural commandment. [This is derived from Numbers 15:18:] "When you come into the land...."9The continuation of the verse describes the mitzvah to separate challah. [Implied is when] all of you enter and not when only a portion enter.10As the Rambam explains in Hilchot Terumah 1:26 and Hilchot Beit HaBechirah 6:16, after the conquest of Eretz Yisrael by Assyrians and the Babylonians the sanctity of the land was nullified and there was no obligation to keep the agricultural laws of Eretz Yisrael. When Ezra led the people back to Eretz Yisrael after the 70 years of the Babylonian exile, the majority of the people did not accompany him. (Moreover, he did not conquer the land.) Hence, his sanctification of Eretz Yisrael was not sufficient to meet the requirements of Scriptural Law. Nevertheless, he and his court ruled that those mitzvot should be observed as a Rabbinic ordinance.
This reflects the Rambam's view. Although other Rishonim (Ra'avad, Rav Moshe HaCohen) differ and maintain that Ezra's settlement of the land was sufficient to sanctify it according to Scriptural Law, the Rambam's approach is accepted by most authorities.
When Ezra ascended [to Eretz Yisrael], the entire people did not ascend.
Similarly, in the present era, terumah is a Rabbinic commandment.11The Rambam maintains that the laws regarding terumah and the tithes are derived from those applying to challah (Kessef Mishneh to Hilchot Terumah 1:26). Therefore it is eaten by the priests of our era [whose lineage is established merely] by presumption.

הלכה ד
מִי שֶׁהֵעִידוּ עָלָיו [שְׁנֵי] עֵדִים שֶׁרָאוּהוּ שֶׁהָיָה אוֹכֵל בִּתְרוּמָה שֶׁל תּוֹרָה הֲרֵי זֶה מְיֻחָס. וְאֵין מַעֲלִין לְיוּחֲסִין לֹא מִנְּשִׂיאַת כַּפַּיִם וְלֹא מִקְּרִיאָה בַּתּוֹרָה רִאשׁוֹן וְלֹא מֵחִלּוּק תְּרוּמָה בְּבֵית הַגְּרָנוֹת וְלֹא עַל פִּי עֵד אֶחָד:
כסף משנה
4.
When two witnesses testify that they saw a person partaking of terumah mandated by Scriptural Law, his lineage is established. We do not elevate a person [to the level that his priestly] lineage is [considered as] established based on the fact that he delivers the Priestly Blessing [to the people], reads the Torah first,12In the Talmudic era - as is still the practice in certain communities - when a person was given an aliyah, he would read the Torah himself, rather than have it read for him by others. or is given terumah in the granaries,13Although all of these practices are signs of the priesthood, we do not consider them as conclusive evidence of a priest's lineage. or because of the testimony of one witness.

הלכה ה
כֹּהֵן מְיֻחָס שֶׁאָמַר בְּנִי זֶה כֹּהֵן הוּא אֵין מַעֲלִין אוֹתוֹ לְיוּחֲסִין עַל פִּיו עַד שֶׁיָּבִיא עֵדִים שֶׁהוּא בְּנוֹ:
כסף משנה
5.
When a priest whose lineage was established says: "This son of mine is a priest," we do not consider [the son as a priest whose] lineage is established14The Maggid Mishneh explains that the Rambam's words could be interpreted to mean that the child is considered a priest with regard to marriage. Nevertheless, he does not possess the advantage of being considered of established lineage unless testimony is given. on the basis of his statement unless he brings witnesses who testify that the child is his son.15The father's statement is, however, sufficient to have considered as a priest with regards to matters applicable in the present age, as stated in Halachah 10.

הלכה ו
כֹּהֵן מְיֻחָס שֶׁיָּצָא הוּא וְאִשְׁתּוֹ שֶׁיָּדַעְנוּ שֶׁהִיא כְּשֵׁרָה לִמְדִינָה אַחֶרֶת וּבָא הוּא וְהִיא וּבָנִים כְּרוּכִין אַחֲרֵיהֶן וְאָמַר אִשָּׁה שֶׁיָּצָאת עִמִּי הִיא זוֹ וְאֵלּוּ בָּנֶיהָ אֵינוֹ צָרִיךְ לְהָבִיא עֵדִים לֹא עַל הָאִשָּׁה וְלֹא עַל הַבָּנִים. מֵתָה וְאֵלּוּ בָּנֶיהָ צָרִיךְ לְהָבִיא עֵדִים שֶׁאֵלּוּ בָּנָיו. וְאֵינוֹ צָרִיךְ לְהָבִיא עֵדִים עַל אִמָּן שֶׁהִיא כְּשֵׁרָה. מִפְּנֵי שֶׁכְּבָר הֻחְזַק שֶׁיָּצְאָה מֵעִמָּנוּ כְּאִשָּׁה כְּשֵׁרָה:
כסף משנה
6.
[The following laws apply when] a priest whose lineage has been established departs to another country together with his wife whom we know to be of acceptable lineage. If he comes together with her and children who relate to them as parents and says: "This is the woman who departed together with me and these are her children," he does not have to bring witnesses to testify about the woman or the children.
[If he says:] "She died and these are her children," he must bring witnesses who testify that these are his children.16More precisely, that they are the sons borne him by his deceased wife. He need not bring witnesses that his wife was of acceptable lineage, for her status as being acceptable was already established when she departed from us.

הלכה ז
יָצָא כֹּהֵן מְיֻחָס לִמְדִינָה אַחֶרֶת וּבָא הוּא וְאִשְׁתּוֹ וּבָנָיו וְאָמַר אִשָּׁה זוֹ נָשָׂאתִי וְאֵלּוּ בָּנֶיהָ צָרִיךְ לְהָבִיא רְאָיָה שֶׁאִשָּׁה זוֹ כְּשֵׁרָה. וְאֵינוֹ מֵבִיא עֵדִים שֶׁאֵלּוּ בָּנֶיהָ. וְהוּא שֶׁיִּהְיוּ כְּרוּכִין אַחֲרֶיהָ. וְאִם בָּא בִּשְׁתֵּי נָשִׁים וְהֵבִיא רְאָיָה עַל הָאַחַת אַף עַל פִּי שֶׁהַבָּנִים קְטַנִּים וּכְרוּכִין אַחֲרֶיהָ צָרִיךְ לְהָבִיא רְאָיָה עֲלֵיהֶם שֶׁמָּא בָּנָיו מִן הָאַחֶרֶת הֵם וְנִכְרְכוּ אַחַר זוֹ הַמְיֻחֶסֶת:
כסף משנה
7.
When a priest whose lineage was established goes out to another country and comes together with his wife and his sons, saying: "I married this woman and these are her sons," he must bring proof that the woman is acceptable. He does not have to bring witnesses that these are her sons, provided the children relate to her as a mother.
If he comes together with two wives and brings proof regarding one, he is required to bring proof about the sons, even though the children are young and relate to her as a mother. For perhaps they are the sons of the other women, but relate to the woman whose lineage is established as a mother.

הלכה ח
בָּא הוּא וּבָנָיו וְאָמַר אִשָּׁה נָשָׂאתִי וָמֵתָה וְאֵלּוּ בָּנֶיהָ מֵבִיא עֵדִים שֶׁאוֹתָהּ הָאִשָּׁה כְּשֵׁרָה הָיְתָה וְאֵלּוּ בָּנֶיהָ. וְכַדִּין הַזֶּה דָּנִין בְּיִשְׂרָאֵל מְיֻחָס וּבְלֵוִי מְיֻחָס. וְאַחַר כָּךְ נָעִיד עַל בְּנוֹ זֶה שֶׁהוּא מְיֻחָס כְּדֵי שֶׁיִּהְיֶה רָאוּי לְסַנְהֶדְרִין:
כסף משנה
8.
If he comes together with sons and says: "I married a woman and she died. These are her sons," he must bring witnesses that the woman was acceptable and that these are her sons." These laws also apply with regard to an Israelite of established lineage and a Levite of established lineage. Afterwards, we can testify with regard to this son so that he will be fit for the Sanhedrin.17And his daughters fit to marry priests.

הלכה ט
אֵין מַעֲלִין מִשְּׁטָרוֹת לִכְהֻנָּה. כֵּיצַד. הֲרֵי שֶׁהָיָה כָּתוּב בִּשְׁטָר פְּלוֹנִי כֹּהֵן לָוָה מִפְּלוֹנִי וְהִלְוָהוּ כָּךְ וְכָךְ וְהָעֵדִים מִלְּמַטָּה אֵין מַחֲזִיקִין בָּהֶם כֹּהֵן זֶה שֶׁהוּא מְיֻחָס שֶׁמָּא לֹא הֵעִידוּ אֶלָּא עַל הַמִּלְוֶה. בַּמֶּה דְּבָרִים אֲמוּרִים לְעִנְיַן יִחוּס. אֲבָל לַחֲזָקָה שֶׁיִּהְיֶה כֹּהֵן כְּכֹהֲנֵי זְמַן זֶה וְיֹאכַל תְּרוּמָה וְחַלָּה שֶׁל דִּבְרֵי סוֹפְרִים וּבִשְׁאָר קָדְשֵׁי הַגְּבוּל מַעֲלִין מִן הַשְּׁטָרוֹת וְעַל פִּי עֵד אֶחָד וּמִנְּשִׂיאוּת כַּפַּיִם וּמִקְּרִיאָה בַּתּוֹרָה רִאשׁוֹן:
כסף משנה
9.
We do not elevate a person's lineage [based on mention in] a document to the priesthood. What is implied? If it is stated in a document: "So-and-so, the priest, borrowed from so-and-so this-and-this amount," and witnesses sign below, we do not operate under the assumption that this priest is of acceptable lineage. For perhaps, they signed only with regard to the loan.18And did not pay attention to the fact the person was described as a priest.
With regard to what does the above apply? With regard to considering the person as a priest of acceptable lineage. [Different principles apply] with regard to the presumption that he is a priest like the other priests of the present age and license to partake of terumah and challah mandated by Rabbinic decree and to be given other sacred articles [granted priests within] the boundaries [of Eretz Yisrael].19E.g., the sheep exchanged in place of a donkey, the first shearing of a sheep, and the like. [These privileges are granted on the basis of] mention in a legal document, the testimony of one witness, or the fact that a person recites the priestly blessing or reads the Torah first.

הלכה י
וְכֵן כָּל כֹּהֵן שֶׁאָמַר בְּנִי זֶה כֹּהֵן נֶאֱמָן לְהַאֲכִילוֹ בִּתְרוּמָה וְלִהְיוֹתוֹ בְּחֶזְקַת כֹּהֵן וְאֵינוֹ צָרִיךְ לְהָבִיא רְאָיָה לֹא עַל הַבָּנִים וְלֹא עַל הָאִשָּׁה:
כסף משנה
10.
Similarly, whenever a priest says: "My son is a priest," his word is accepted with regard to feeding him terumah20This refers even to terumah mandated by Scriptural Law. Ketubot 25b explains that this ruling is based on the principle of miggo. If the priest desired to transgress, he could feed his son terumah without having him declared a priest. See also Halachah 3. and having him accepted as a priest.21To be given an aliyah first and to bless the people. He need not bring proof regarding his sons or his wife.

הלכה יא
שְׁנַיִם שֶׁבָּאוּ לִמְדִינָה זֶה אוֹמֵר אֲנִי וַחֲבֵרִי כֹּהֵן וְזֶה אוֹמֵר אֲנִי וַחֲבֵרִי כֹּהֵן אַף עַל פִּי שֶׁנִּרְאִין כְּגוֹמְלִין זֶה אֶת זֶה הֲרֵי אֵלּוּ נֶאֱמָנִין וּשְׁנֵיהֶם בְּחֶזְקַת כֹּהֲנִים. וְכֵן עֵד שֶׁאָמַר רָאִיתִי זֶה שֶׁנָּשָׂא כַּפָּיו אוֹ שֶׁאָכַל בִּתְרוּמָה אוֹ שֶׁחָלַק עַל הַגֹּרֶן אוֹ שֶׁקָּרָא בַּתּוֹרָה רִאשׁוֹן וְקָרָא אַחֲרָיו לֵוִי מַחֲזִיקִין אוֹתוֹ בִּכְהֻנָּה עַל פִּיו. וְכֵן אִם הֵעִיד שֶׁזֶּה קָרָא שֵׁנִי בַּתּוֹרָה אַחַר כֹּהֵן מַחֲזִיקִין אוֹתוֹ בִּלְוִיָּה:
כסף משנה
11.
When two people come to a particular city, one says: "I and my colleague are priests," and the other says, "I and my colleague are priests," their word is accepted and they are both considered as priests22For the testimony of one witness is effective. even though it appears that they are in collusion.23And there is room to suspect that each is lying on the others behalf.
Similarly, if one witness says: "I saw this person recite the Priestly Blessing," "...eat terumah, "...received terumah in the granary," or "...read first from the Torah and a Levi read after him,"24If a Levi did not read after him, the fact that he read first is not significant. For perhaps there were no priests present and an Israelite was called instead or he was given the honor because of his stature as a Torah scholar. he is considered a priest on the basis of this statement. Similarly, if one testified that a person read second from the Torah after a priest, he is considered as a Levite.

הלכה יב
הֵעִיד שֶׁרָאָה זֶה שֶׁחָלַק עִם אָחִיו בְּבֵית דִּין תְּרוּמָה שֶׁהִנִּיחַ לָהֶן אֲבִיהֶן הַכֹּהֵן אֵין מַעֲלִין אוֹתוֹ לִכְהֻנָּה בְּעֵדוּת זוֹ. שֶׁמָּא חָלָל הוּא וְלָקַח חֵלֶק יְרֻשָּׁתוֹ מִתְּרוּמָה לְמָכְרָהּ:
כסף משנה
12.
If one delivers testimony in court saying that he saw a person and his brothers divide terumah left to them by their father the priest, we do not consider him a priest because of this testimony. Perhaps he is a challal and took his portion of the inheritance of terumah in order to sell it.

הלכה יג
מִי שֶׁבָּא בַּזְּמַן הַזֶּה וְאָמַר כֹּהֵן אֲנִי אֵינוֹ נֶאֱמָן וְאֵין מַעֲלִין אוֹתוֹ לִכְהֻנָּה עַל פִּי עַצְמוֹ וְלֹא יִקְרָא בַּתּוֹרָה רִאשׁוֹן וְלֹא יִשָּׂא אֶת כַּפָּיו וְלֹא יֹאכַל בְּקָדְשֵׁי הַגְּבוּל עַד שֶׁיִּהְיֶה לוֹ עֵד אֶחָד. אֲבָל אוֹסֵר עַצְמוֹ בִּגְרוּשָׁה וְזוֹנָה וַחֲלָלָה וְאֵינוֹ מִטַּמֵּא לְמֵתִים. וְאִם נָשָׂא אוֹ נִטְמָא לוֹקֶה. וְהַנִּבְעֶלֶת לוֹ סְפֵק חֲלָלָה:
כסף משנה
13.
In the present era, when a person comes and says: "I am a priest," his word is not accepted and we do not consider him a priest on the basis of his own statements. He should not read from the Torah first, recite the Priestly Blessing,25The Maggid Mishneh explains that the above are forbidden him, because - as stated in Halachah 9 - when an observer sees a person performing such acts, he may consider that person a priest.
Rav Moshe Cohen and the Rama (Even HaEzer 3:1) maintain that, in the present era, it is customary to accept a person's word if he claims to be a priest. For the only serious problem with regard to observance is partaking of terumah and we do not separate terumah in the present age. Note the Chelkat Mechokek 3:1 who raises questions regarding the license for this person to recite the Priestly Blessing. See also the Maggid Mishneh who mentions that this custom was also practiced in his era. He strongly protests against it, calling it "an erroneous custom."
or partake of sacred food that is eaten [within] the boundaries [of Eretz Yisrael] unless there is one witness who corroborates his statements.
He does, however, cause himself to be forbidden [to marry] a divorcee, a zonah, and a challalah; nor may he become impure because of contact with a corpse.26Since he considers himself a priest, it is as if he has taken a vow not to perform these activities. If he marries such a woman or becomes impure, he receives lashes.27The commentaries have questioned this statement, for it has not been formally established that the person is a priest. Nevertheless, since he considers himself a priest, as far as he is concerned, the warning given him will be have been of substance and the punishment deserved. Hence he is given the lashes. The woman is not given lashes, for as far as she is concerned, the matter is not definitely established (Maggid Mishneh). A woman [who may not marry into the priesthood] who engages in relations with him is deemed a challalah of questionable status.28Hence if another priest engages in relations with her, he is not given lashes. Her offspring are also challalim of questionable status and her daughter may not marry into the priesthood (Maggid Mishneh; Chelkat Mechokek 3:3).

הלכה יד
וְאִם הָיָה מֵסִיחַ לְפִי תֻּמּוֹ נֶאֱמָן. כֵּיצַד. מַעֲשֶׂה בְּאֶחָד שֶׁהָיָה מֵסִיחַ לְפִי תֻּמּוֹ וְאָמַר זָכוּר אֲנִי כְּשֶׁהָיִיתִי תִּינוֹק וְהָיִיתִי מֻרְכָּב עַל כְּתֵפוֹ שֶׁל אָבִי הוֹצִיאוּנִי מִבֵּית הַסֵּפֶר וְהִפְשִׁיטוּנִי כֻּתָּנְתִּי וְהִטְבִּילוּנִי לֶאֱכל תְּרוּמָה לָעֶרֶב וַחֲבֵרַי בּוֹדְלִין מִמֶּנִּי וְהָיוּ קוֹרְאִין אוֹתִי יוֹחָנָן אוֹכֵל חַלּוֹת וְהֶעֱלָהוּ רַבֵּנוּ הַקָּדוֹשׁ לִכְהֻנָּה עַל פִּי עַצְמוֹ:
כסף משנה
14.
If the person makes these statements in the course of conversation, his word is accepted.29He is allowed to partake of terumah mandated by Rabbinic decree, for his statements are given the weight of the testimony of one witness.
What is implied? An incident once took place with regard to a person who was speaking in the midst of conversation, saying: "I remember that when I was an infant and was being carried on my shoulders by father, they took me out of school,30This is proof that he was not a servant, for servants are not taught the Torah (Tosafot, Ketubot 26a). removed my outer garment, and had me immerse in the mikveh to partake of terumah in the evening. My colleagues separated themselves from me and called me: 'Yochanan, who eats challot.' Our holy teacher31Rabbi Yehudah HaNasi. had him considered a priest on the basis of these statements.

הלכה טו
נֶאֱמָן גָּדוֹל לוֹמַר זָכוּר אֲנִי כְּשֶׁהָיִיתִי תִּינוֹק וְרָאִיתִי פְּלוֹנִי טוֹבֵל וְאוֹכֵל בִּתְרוּמָה לָעֶרֶב וּמַחֲזִיקִין אוֹתוֹ בִּכְהֻנָּה בְּעֵדוּתוֹ. מִי שֶׁבָּא בַּזְּמַן הַזֶּה וְאָמַר כֹּהֵן אֲנִי וְעֵד אֶחָד מֵעִיד לוֹ שֶׁאֲנִי יוֹדֵעַ שֶׁאָבִיו שֶׁל זֶה כֹּהֵן אֵין מַעֲלִין אוֹתוֹ לִכְהֻנָּה בְּעֵדוּת זֶה שֶׁמָּא חָלָל הוּא עַד שֶׁיָּעִיד שֶׁזֶּה כֹּהֵן הוּא. אֲבָל אִם הֻחְזַק אָבִיו כֹּהֵן אוֹ שֶׁבָּאוּ שְׁנַיִם וְהֵעִידוּ שֶׁאָבִיו שֶׁל זֶה כֹּהֵן הֲרֵי הוּא בְּחֶזְקַת אָבִיו:
כסף משנה
15.
An adult's word is accepted if he says: "I remember when I was a child32Generally, for testimony to be valid, the person observing the matter must be acceptable as a witness. In this instance, however, formal testimony is not required. Hence leniency is shown. (See Hilchot Edut 14:3). and I saw so-and-so immerse himself in a mikveh and partake of terumah in the evening." He is considered a priest on the basis of this statement.
In the present era, when a person comes and says: "I am a priest," and a witness testifies on his behalf, saying: "I know that his father is a priest," we do not consider him as a priest on the basis of this testimony. [We fear that] perhaps he is a challal.33This applies even if there are no rumors that the person's mother is not acceptable (Maggid Mishneh). The Chelkat Mechokek 3:9 quotes other authorities who are more lenient. Instead, [the witness] must testify that the person himself is a priest. If, however, the father's identity as a priest is an established fact or two witnesses come and testify that the person's father is a priest, because of his father, we assume [that he is a priest].

הלכה טז
מִי שֶׁהֻחְזַק אָבִיו כֹּהֵן וְיָצָא עָלָיו קוֹל שֶׁהוּא בֶּן גְּרוּשָׁה אוֹ חֲלוּצָה חוֹשְׁשִׁין לוֹ וּמוֹרִידִין אוֹתוֹ. בָּא עֵד אֶחָד אַחַר כָּךְ וְהֵעִיד שֶׁהוּא כָּשֵׁר מַעֲלִין אוֹתוֹ לִכְהֻנָּה עַל פִּיו. בָּאוּ שְׁנַיִם עֵדִים אַחַר כָּךְ וְהָעִידוּ שֶׁהוּא חָלָל מוֹרִידִין אוֹתוֹ מִן הַכְּהֻנָּה. בָּא עֵד אֶחָד וְהֵעִיד שֶׁהוּא כָּשֵׁר מַעֲלִין אוֹתוֹ לִכְהֻנָּה שֶׁזֶּה הָאַחֲרוֹן מִצְטָרֵף לְעֵד רִאשׁוֹן וַהֲרֵי שְׁנַיִם מְעִידִין שֶׁהוּא כָּשֵׁר וּשְׁנַיִם מְעִידִים שֶׁהוּא פָּסוּל יִדָּחוּ אֵלּוּ וְאֵלּוּ וְיִדָּחֶה הַקּוֹל שֶׁהַשְּׁנַיִם כְּמֵאָה וְיִשָּׁאֵר כֹּהֵן בְּחֶזְקַת אָבִיו:
כסף משנה
16.
When the identity of a person's father as a priest has been established, but there is a rumor34We are not speaking about mere hearsay, but a rumor that is substantiated by the court. that he is the son of a divorcee or the son of a woman who performed chalitzah, we entertain suspicions and do not treat him as a priest. If one witness comes and testifies that he is acceptable, we treat him as a priest because of his statements.35For the testimony of one witness is powerful enough to negate the rumor. If two witnesses come afterwards and testify that he is a challal, we remove him from the priesthood.36Because the testimony of one witness is of no consequence in the face of the testimony of two witnesses.
If another witness comes and testifies that he is acceptable, we treat him as a priest, because the last witness is joined together with the first.37The fact that the two witnesses do not testify at the same time is not significant (Hilchot Edut 4:4). Thus there are two witnesses testifying that he is acceptable and two testifying that he is unacceptable. Both pairs of witness and the rumor are voided, for two witnesses have the same legal power as 100.38I.e., the intent is that once two witnesses give testimony in court, their statement is given the weight of established fact and needs no further corroboration. Since the statements of the two pairs of witnesses contradict each other, they are both nullified. Nevertheless, the statements of the witnesses who testify that he is acceptable also have the power to nullify the rumor. And the person remains a priest based on the status of his father.39The Maggid Mishneh mentions that there is a difference of opinion among the Rabbis if he is considered acceptable only with regard to terumah mandated by Rabbinic Law or also with regard to terumah mandated by Scriptural Law. The Beit Shmuel 3:14 states that the Rambam is also referring to terumah mandated by Rabbinic Law.

הלכה יז
אִשָּׁה שֶׁלֹּא שָׁהֲתָה שְׁלֹשָׁה חֳדָשִׁים אַחַר בַּעְלָהּ וְיָלְדָה. וְאֵין יָדוּעַ אִם בֶּן תִּשְׁעָה לְרִאשׁוֹן אוֹ בֶּן שִׁבְעָה לְאַחֲרוֹן וְהָיָה אֶחָד מֵהֶן כֹּהֵן וְהַשֵּׁנִי יִשְׂרָאֵל הֲרֵי זֶה סְפֵק כֹּהֵן. וְכָךְ אִם נִתְעָרֵב וְלַד כֹּהֵן בִּוְלַד יִשְׂרָאֵל וְהִגְדִּילוּ הַתַּעֲרוֹבוֹת כָּל אֶחָד מֵהֶן סְפֵק כֹּהֵן. וְנוֹתְנִין עֲלֵיהֶן חֻמְרֵי יִשְׂרָאֵל וְחֻמְרֵי כֹּהֲנִים. נוֹשְׂאִין נָשִׁים הָרְאוּיוֹת לִכְהֻנָּה וְאֵין מִטַּמְּאִים לְמֵתִים וְלֹא אוֹכְלִין בִּתְרוּמָה. וְאִם נָשְׂאוּ גְּרוּשָׁה מוֹצִיאִין וְאֵינָן לוֹקִין:
כסף משנה
17.
[The following law applies] when a woman [remarried] without waiting three months after [the death of] her [first] husband40A woman is required to wait for such an interim so that the lineage of her children will be established definitively. and gave birth. If it is not known whether the child was conceived by the first - and born after nine months - or conceived by the second - and born after seven - and one of them was a priest and the other, an Israelite, the child is a priest of questionable status.
Similarly, if a son of a priest became intermingled with a child of an Israelite41I.e., as infants, the identity of the children became confused and the doubt was never clarified. and they grow to maturity, they are both considered priests of questionable status. They must observe the stringencies incumbent on Israelites and the stringencies incumbent on priests: They may only marry women fit to marry into the priesthood. They may not become impure through contact with the dead, nor may they partake of terumah. If they marry a divorcee, they are forced to divorce and they do not receive lashes.42They are not given lashes, because it is not certain that they violated a Scriptural commandment. They should, however, be given "stripes for rebellious conduct," because of their disregard of the restrictions the Rabbis placed upon them [Perisha (Even HaEzer 3)].

הלכה יח
שְׁנֵי כֹּהֲנִים שֶׁנִּתְעָרְבוּ וַלְדוֹתֵיהֶם. אוֹ אֵשֶׁת כֹּהֵן שֶׁלֹּא שָׁהֲתָה אַחַר בַּעְלָהּ שְׁלֹשָׁה חֳדָשִׁים וְנִשֵּׂאת לְכֹהֵן אַחֵר וְאֵין יָדוּעַ אִם בֶּן תִּשְׁעָה לָרִאשׁוֹן אוֹ בֶּן שִׁבְעָה לָאַחֲרוֹן. נוֹתְנִין לוֹ עַל הַוָּלָד חֻמְרֵי שְׁנֵיהֶם. הוּא אוֹנֵן עֲלֵיהֶם וְהֵן אוֹנְנִין עָלָיו. הוּא אֵין מְטַמֵּא לָהֶם וְהֵם אֵינָן מְטַמְּאִין לוֹ. וְעוֹלֶה בְּמִשְׁמָרוֹ שֶׁל זֶה וְשֶׁל זֶה. וְאֵין חוֹלֵק. וְאִם הָיוּ שְׁנֵיהֶם בְּמִשְׁמָר אֶחָד וּבֵית אָב אֶחָד נוֹטֵל חֵלֶק אֶחָד:
כסף משנה
18.
[The following rules apply] if the sons of two priests become intermingled or the wife of a priest married a second priest without waiting three months after the death of her first husband and it is not known whether the child was conceived by the first - and born after nine months - or conceived by the second - and born after seven. The stringencies that would apply as if he was the son of both men must be observed: He must observe the rites of aninut43This term refers to the state of acute morning that applies immediately after the death of one's close relative. See Hilchot Evel 4:6. It is particularly relevant to priests, for one is forbidden to serve in the Temple or partake of sacrificial foods in a state of aninut (Hilchot Bi'at HaMikdash 2:6-10 ). because of [both44Yevamot 100b notes a difficulty in the use of the plural in both this and the following clause. Since the ordinary way the mother of this priest could have married a second priest is when her first husband died, how is it possible to speak about the son mourning for that first husband or that first husband mourning for him?
The Talmud answers that this is speaking about a situation where the mother thought she was consecrated to the first husband, but in fact was not. This is not considered a licentious relationship warranting the stringencies mentioned in the following halachah. A formal divorce, however, is not required and hence the woman may marry another priest.
The Maggid Mishneh explains that according to the Rambam, one can also interpret the passage as referring to a woman whose father died in her childhood and who was married by Rabbinic decree. Until she attains majority, she may dissolve that marriage through the rite of mi'un. In such an instance, a formal divorce is not required. If she conceives a child, dissolves her marriage, and then marries another priest, the situation mentioned in this halachah may apply.
of] them45For perhaps that person is his father. Rashi (Yevamot, loc. cit.) interprets this statement as referring to the restrictions placed upon priests for aninut. Since it is possible that the person who died is his father, he should not risk the violation of a Scriptural commandment. With regard to the customs concerning aninut mentioned in Hilchot Evel (one of them being that one does not perform any of the Torah's mitzvot), by contrast, Kinat Eliyahu raises a question: Should one refrain from performing a mitzvah because perhaps the person who died was his father? and they [both] observe the rights of aninut because of him.46For perhaps he is their son. He may not become impure because of them, nor may they become impure because of him.47There is a Scriptural prohibition against a priest becoming impure. That prohibition does not apply when one is certain that the person who died is one's relative. In this instance, however, neither the father or son is certain. He may serve in the priestly watch48The priests were divided into 24 watches. Each one would serve in the Temple for a week in a cycle of rotation (Hilchot K'lei HaMikdash 4:3). This priest has the right to serve during the week allotted to both of the individuals suspected of being his father. of both of them, but does not receive a portion.49In this instance, we are speaking of expropriating property (a share in the sacrifices) from the other priests. Hence we follow the principle: When a person seeks to expropriate property, the burden of proof is upon him. If they are both from the same priestly watch and the same beit av,50Each priestly watch was divided into seven batei av, family groupings, who would serve in the Temple one day of the seven (Hilchot K'lei HaMikdash 4:11). he receives one portion.51For he is certainly entitled to one portion.

הלכה יט
בַּמֶּה דְּבָרִים אֲמוּרִים בִּזְמַן שֶׁהֵן בָּאִין מִכֹּחַ נִשּׂוּאִין. אֲבָל בִּזְנוּת גָּזְרוּ חֲכָמִים שֶׁמְּשַׁתְּקִין אוֹתוֹ מִדִּין כְּהֻנָּה כְּלָל הוֹאִיל וְאֵינוֹ יוֹדֵעַ אָבִיו הַוַּדַּאי שֶׁנֶּאֱמַר (במדבר כה יג) "וְהָיְתָה לּוֹ וּלְזַרְעוֹ אַחֲרָיו" עַד שֶׁיִּהְיֶה זַרְעוֹ מְיֻחָס אַחֲרָיו:
כסף משנה
19.
When does the above apply? When the relationships with both [priests] involve marriage. If, however, one is a licentious relationship, our Sages decreed that [the son's] priestly privileges are suppressed entirely, because he does not have definitive knowledge of the identity of his father. [This is supported by Numbers 25:13]:52Yevamot, loc. cit., explains that this interpretation is not of Scriptural origin. Instead, the law is a Rabbinic decree. Our Sages, however, found a Biblical verse that supported their ruling. "He and his descendants who follow him will possess [the covenant of priesthood]." [Implied is that] his descendants will be able to trace their identity to him.

הלכה כ
כֵּיצַד. עֲשָׂרָה כֹּהֲנִים שֶׁפֵּרַשׁ אֶחָד מֵהֶם וּבָעַל שֶׁהֲרֵי הַוָּלָד כֹּהֵן וַדַּאי וְאַף עַל פִּי כֵן הוֹאִיל וְאֵינוֹ יוֹדֵעַ אָבִיו שֶׁיִּתְיַחֵס לוֹ מְשַׁתְּקִין אוֹתוֹ מִדִּין כְּהֻנָּה. וְאֵינוֹ עוֹבֵד וְלֹא אוֹכֵל וְלֹא חוֹלֵק. וְאִם נִטְמָא לְמֵתִים אוֹ נָשָׂא גְּרוּשָׁה לוֹקֶה שֶׁאֵין כָּאן סְפֵק הֶתֵּר:
כסף משנה
20.
What is implied? There were ten priests. One of them departed and engaged in relations [with a woman without revealing his identity]. The son is definitely a priest.53Because all the individuals suspected of being his father were priests. Nevertheless, since he does not know his father's identity and cannot trace his lineage to him, his priestly privileges are suppressed entirely. He may not serve [in the Temple], partake [of sacrificial foods], or receive an allotment [from the sacrifices]. If, however, he becomes impure because of contact with a corpse or he marries a divorcee, he receives lashes, for there is no question of leniency.54For he is definitely a priest and must observe the prohibitions incumbent upon them.

קדושה הלכות איסורי ביאה פרק כ
Kedushah Issurei Biah Chapter 20