Halacha

הלכה א
הַלוֹקֵחַ פֵּרוֹת מִמִּי שֶׁאֵינוֹ נֶאֱמָן עַל הַמַּעַשְׂרוֹת וְשָׁכַח לְעַשְּׂרָן וְנִכְנְסָה שַׁבָּת אוֹ יוֹם טוֹב שֶׁאֵינוֹ יָכוֹל לְעַשֵּׂר הֲרֵי זֶה שׁוֹאֲלוֹ. וְאִם אָמַר לוֹ מְעֻשָּׂרִין הֵן אוֹכֵל עַל פִּיו בְּשַׁבָּת. וְכֵן אִם אָמַר לוֹ אֶחָד שֶׁאֵינוֹ נֶאֱמָן מְעֻשָּׂרִין הֵן אוֹכֵל עַל פִּיו בְּאוֹתָהּ שַׁבָּת. וַאֲפִלּוּ הָיוּ לוֹ פֵּרוֹת אֲחֵרוֹת מְתֻקָּנִין מֵאוֹתוֹ הַמִּין מִפְּנֵי שֶׁאֵימַת שַׁבָּת עַל עַמֵּי הָאָרֶץ וְאֵינוֹ עוֹבֵר בָּהּ עֲבֵרָה:
כסף משנה
1.
When a person purchases produce from a person upon whom we do not rely with regard to the tithes1From Halachah 16, it is apparent that here the Rambam is speaking about a common person whose level of observance is a matter of doubt. If, however, it is known that a person is lax with regard to the separation of tithes, his word is not accepted even on the Sabbath. and forgot2The Jerusalem Talmud (Demai 4:1) emphasizes that this leniency is granted only when a person failed to tithe out of forgetfulness. If he intentionally did not tithe the produce, there is no leniency upon which he can rely to partake of it on the Sabbath. to tithe it before the commencement of the Sabbath or a festival - upon which he may not tithe it3Hilchot Shabbat 23:9, 14; Shvitat Yom Tov 4:26. - he should ask that person regarding their status. If he tells him that it is tithed, he may rely on his word on [that] Sabbath.4Because of the holiness of the day, the common people regard transgressing on the Sabbath as more severe than transgressing on other days [the Rambam's Commentary to the Mishnah (Demai 4:1)].
Similarly, if another person upon whom we cannot rely tells him that it was tithed, he may partake of it because of his word on that Sabbath.5In his Commentary to the Mishnah (ibid.), the Rambam notes that there is a general principle (Kiddushin 63b) that a person will not sin unless he personally benefits. Thus one might think that we could rely on this person's word, even during the week. Hence, it is necessary to explain that we rely on his statements only on the Sabbath. The rationale is that the presumption that he will not lie applies to most people. There are, however, some that will lie even on the Sabbath [the Jerusalem Talmud (Demai 4:1)]. [This applies] even if he possesses other produce of that type from which the separations have been made. [The rationale is that] the awe of Sabbath affects the common people and they will not violate a transgression on that day.

הלכה ב
אַף עַל פִּי שֶׁהוּא אוֹכֵל עַל פִּיו בְּשַׁבָּת הֲרֵי זֶה לֹא יֹאכַל מֵאוֹתָן הַפֵּרוֹת לְמוֹצָאֵי שַׁבָּת עַד שֶׁיְּעַשֵּׂר דְּמַאי עַל הַכּל עַל שֶׁאָכַל בְּשַׁבָּת וְעַל הַנִּשְׁאָר שֶׁלֹּא הֵקֵלּוּ וְהֶאֱמִינוּהוּ אֶלָּא לְצֹרֶךְ אוֹתָהּ שַׁבָּת. הָיְתָה שַׁבָּת וְיוֹם טוֹב סָמוּךְ לָהּ וּשְׁאָלוֹ בְּאֶחָד מֵהֶן אוֹכֵל אַף בַּשֵּׁנִי. מִפְּנֵי שֶׁלֹּא נִרְאֶה לְעַשֵּׂר בֵּינְתַיִם. וְכֵן בִּשְׁנֵי יָמִים טוֹבִים שֶׁל גָּלֻיּוֹת:
כסף משנה
2.
Even though one relies on the word of a common person to eat on the Sabbath, he should not partake of that produce after the conclusion of the Sabbath until he separates the tithes as appropriate for demai for the entire amount, what he ate on the Sabbath and what remains. For the leniency [to] trust him was granted only out of necessity for that Sabbath.6The Rambam is clarifying that the statement made in Halachah 2: that we trust that the common person will not lie on the Sabbath is conditional. It is a leniency accepted to allow a person to honor the Sabbath alone.
If the Sabbath and a festival followed in succession,7I.e., the festival fell on Friday or on Sunday. if one asked [a common person concerning produce] on one, he may partake of it on the other,8This leniency is granted even though the two days are not considered as a single continuum of holiness (see Hilchot Eruvin 8:5). because he did not have the opportunity to tithe in the interim. Similar laws apply with regard to the two days [for each festival celebrated] in the Diaspora.

הלכה ג
הַנִּשְׁבָּע עַל חֲבֵרוֹ שֶׁיֹּאכַל עִמּוֹ בְּשַׁבָּת וְהוּא אֵינוֹ מַאֲמִינוֹ עַל הַמַּעַשְׂרוֹת שׁוֹאֵל וְאוֹכֵל עַל פִּיו בַּשַּׁבָּת הָרִאשׁוֹנָה בִּלְבַד. אֲבָל בְּשַׁבָּת שְׁנִיָּה אַף עַל פִּי שֶׁנָּדַר מִמֶּנּוּ הֲנָאָה אִם לֹא יֹאכַל אֶצְלוֹ לֹא יֹאכַל עַד שֶׁיְּעַשֵּׂר דְּמַאי:
כסף משנה
3.
When a person takes an oath9I.e., he takes an oath that he will never benefit from him unless he partakes of his hospitality [the Rambam's Commentary to the Mishnah (Demai 4:3)]. (Although the mishnah speaks of taking a vow, the Rambam speaks of an oath.) The oath is taken to emphasize to the colleague that the failure to accept his hospitality is a sign of serious enmity between them. Hence, this leniency was granted to encourage feelings of closeness.
Kaftor VePerach, ch. 39, states that we are speaking about a situation where the oath was taken on the Sabbath itself. Otherwise, the guest could make a stipulation allowing for a retroactive separation as described in Chapter 9, Halachah 7. The Radbaz, by contrast, states that we are speaking about a situation where the interaction took place during the week. Otherwise, there would be nothing new taught by this halachah, everything could be understood from the previous one.
that a colleague partake of his hospitality on the Sabbath, but [the guest] does not trust [the host] with regard to tithes, he may ask him10Whether the tithes were separated or not. and eat based on his statements the first Sabbath. On the second Sabbath, even though he took an oath not to benefit from him unless he accepts his hospitality, he should not eat until he tithes as one does for demai.

הלכה ד
מִי שֶׁאֵינוֹ נֶאֱמָן שֶׁרְאִינוּהוּ שֶׁהִפְרִישׁ תְּרוּמַת מַעֲשֵׂר מִפֵּרוֹתָיו שֶׁהֵן דְּמַאי וּרְאִינוּהוּ שֶׁחָזְרָה וְנָפְלָה בְּפָנֵינוּ בֵּין לְמָקוֹם אַחֵר בֵּין לִמְקוֹמָהּ וְחָזַר וְאָמַר הִפְרַשְׁתִּיהָ נֶאֱמָן אֲפִלּוּ בְּחל וְאוֹכֵל עַל פִּיו. כְּשֵׁם שֶׁאֵימַת שַׁבָּת עַל עַמֵּי הָאָרֶץ כָּךְ אֵימַת דִּמּוּעַ עֲלֵיהֶם וְאֵינָן חֲשׁוּדִין לְהַאֲכִיל אֶת הַמְדֻמָּע:
כסף משנה
4.
When we see a person who is not trustworthy11From Halachah 16, it is apparent that here the Rambam is speaking about a common person whose level of observance is a matter of doubt. If, however, it is known that a person is lax with regard to the separation of tithes, his word is not accepted even on the Sabbath. [with regard to the separation of tithes] separate terumat ma'aser from produce belonging to him that is demai and we saw that it later fell back in, whether to that [store of produce] or another and he said: "I separated it,"12I.e., the terumat ma'aser fell in a manner in which it was distinct and could easily be separated from the store of produce. we accept his word - even during the week - and may partake of the produce on that basis. Just as the common people are in dread of the Sabbath,13As stated in Halachah 2. so too, they are in dread of dimua,14Produce into which terumah or terumat ma'aser has been mixed. The rationale is that partaking of such substances is punishable by death at the hand of Heaven. and they are not suspect to cause others to partake of such produce.15The Ra'avad objects to the Rambam's ruling. The Radbaz and the Kessef Mishneh offer interpretations that substantiate the Rambam's ruling.

הלכה ה
מִי שֶׁאֵינוֹ נֶאֱמָן שֶׁרְאִינוּהוּ שֶׁהִפְרִישׁ מַעֲשֵׂר רִאשׁוֹן מִפֵּרוֹת אֵלּוּ וְאָמַר שֶׁהִפְרִישׁ מֵהֶן מַעֲשֵׂר שֵׁנִי נֶאֱמָן. הִפְרִישׁ מַעֲשֵׂר שֵׁנִי בְּפָנֵינוּ וְאָמַר שֶׁהִפְרִישׁ מַעֲשֵׂר רִאשׁוֹן אֵינוֹ נֶאֱמָן שֶׁהַשֵּׁנִי שֶׁלּוֹ. וְהַנֶּאֱמָן עַל הַשֵּׁנִי אֵינוֹ נֶאֱמָן עַל הָרִאשׁוֹן. וְהַנֶּאֱמָן עַל הָרִאשׁוֹן נֶאֱמָן עַל הַשֵּׁנִי. לְפִיכָךְ מִי שֶׁאֵינוֹ נֶאֱמָן שֶׁהוֹצִיא פֵּרוֹת מִבֵּיתוֹ וְאָמַר אֵלּוּ מַעֲשֵׂר רִאשׁוֹן נֶאֱמָן. וְאֵין מַפְרִישִׁין מֵהֶן תְּרוּמוֹת וּמַעַשְׂרוֹת. וְאִם אָמַר אֵלּוּ מַעֲשֵׂר שֵׁנִי אֵינוֹ נֶאֱמָן וַהֲרֵי הֵן דְּמַאי וּמַפְרִישִׁין מֵהֶן תְּרוּמַת מַעֲשֵׂר. וְיֵרָאֶה לִי שֶׁהוּא פּוֹדֶה אֶת כֻּלָּם:
כסף משנה
5.
When we see that a person who is not trustworthy separates the first tithes from such produce and he says that he separated the second tithes, his word is accepted.16The Jerusalem Talmud (Demai 4:1) explains the logic: If he is willing to separate the first tithe which is given to a Levite, he is certainly willing to separate the second tithe which remains his own (but must be eaten in Jerusalem). See Halachah 15. If he separated the second tithe in our presence and said that he separated the first tithe, his word is not accepted, because the second tithe belongs to him.17While the first tithe must be given away as above. [Thus] one who is trusted with regard to the second tithe is not trusted with regard to the first, but one who is trusted with regard to the first is trusted with regard to the second.
Accordingly, when a person who is not trusted brings produce from his home and says: "This is the first tithe," his word is accepted18The Ra'avad objects to this ruling, stating that it is not necessarily a logical continuation of the ruling in the previous clause. and there is no need to separate terumot19I.e., terumah and terumat ma'aser, if he said that he made these separations (Kessef Mishneh). and tithes20I.e., both the first tithe and the second tithe. from [the produce separated].21This bracketed addition represents the resolution offered by the Radbaz and the Kessef Mishneh to the Ra'avad's objection. If he says: "This is the second tithe," his word is not accepted. [The produce separated] is considered as demai and we must separate terumat ma'aser from it. It appears to me that he must redeem the entire amount.22I.e., even the amount separated as terumat ma'aser. For although we are stringent and do not accept his word, we do not reject his statements entirely. Certainly, he himself must bear their consequences and consider the separated produce as if it is required to be redeemed (Radbaz).

הלכה ו
הָאוֹמֵר לְמִי שֶׁאֵינוֹ נֶאֱמָן עַל הַמַּעַשְׂרוֹת קַח לִי מִמִּי שֶׁהוּא מְעַשֵּׂר וְהָלַךְ וְלָקַח וְהֵבִיא לוֹ אֵינוֹ נֶאֱמָן. וְאִם אָמַר לוֹ קַח לִי מֵאִישׁ פְּלוֹנִי הֲרֵי זֶה נֶאֱמָן לוֹמַר מִמֶּנּוּ לָקַחְתִּי שֶׁהֲרֵי מִתְיָרֵא שֶׁמָּא יִשְׁאָלֶנּוּ. הָלַךְ לִקַּח לוֹ מֵאוֹתוֹ פְּלוֹנִי וְאָמַר לוֹ מְצָאתִיו וְלָקַחְתִּי לְךָ מֵאַחֵר שֶׁהוּא נֶאֱמָן אֵינוֹ נֶאֱמָן:
כסף משנה
6.
When one tells a person whose word is not accepted with regard to the tithes: "Purchase [produce] for me from someone who tithes." And that person went and brought him produce, his word is not accepted.23Since he is not trustworthy in this regard, his word is not accepted with regard to others as well. Even though one might say that he would not lie since his falsehood could easily be revealed, for it is possible to ask the identity of the seller and determine if he is trustworthy, the agent could always excuse himself saying: "I thought he was trustworthy" (Radbaz).
Although one might argue that there is no reason for him to sin, for he will not benefit from it, that argument is not accepted. For the ease the person experiences in bringing the produce from a close person could be considered enough of a benefit to influence him to lie.
If he told him: "Purchase [produce] for me from so-and-so," the other person's word is accepted if he says that he purchased it from him, for he will fear [to lie], lest [the principal] ask that person.24And the lie be detected. If he went to purchase [the produce] from the person who was named, but said: "I could not find him, so I purchased it for you from another person who is trustworthy," his word is not accepted.

הלכה ז
הַנִּכְנָס לְעִיר וְאֵינוֹ מַכִּיר אָדָם שָׁם וְאָמַר מִי כָּאן נֶאֱמָן מִי כָּאן מְעַשֵּׂר וְאָמַר לוֹ אֶחָד אֲנִי. אֵינוֹ נֶאֱמָן. אָמַר לוֹ אִישׁ פְּלוֹנִי הֲרֵי זֶה נֶאֱמָן. וְלוֹקֵחַ מֵאוֹתוֹ פְּלוֹנִי אַף עַל פִּי שֶׁאֵינוֹ מַכִּירוֹ וְהוֹלֵךְ וְאוֹכֵל עַל פִּיו. הָלַךְ וְלָקַח מִמֶּנּוּ וְשָׁאַל לוֹ מִי כָּאן מוֹכֵר יַיִן יָשָׁן אָמַר לוֹ זֶה שֶׁשְּׁלָחֲךָ אֶצְלִי אַף עַל פִּי שֶׁהֵן כְּגוֹמְלִין זֶה אֶת זֶה הֲרֵי אֵלּוּ נֶאֱמָנִין:
כסף משנה
7.
[The following rules apply when a person] enters a city where he does not know anyone and asks: "Who is trustworthy? Who tithes?" If someone answers: "I am," his word is not accepted.25Because he would personally benefit from the wayfarer's acceptance of his statements.
The Ra'avad clarifies the Rambam's ruling, noting that his text of the Jerusalem Talmud (Demai 4:5) states: "In the presence [of the person being recommended], his word is not accepted. Outside his presence, his word is accepted." The Radbaz states that this concept is implied by the Rambam's words, since "so-and-so" implies that the person is not present. The Kessef Mishneh interprets the standard version of the Jerusalem Talmud as follows: "If he says he is not trustworthy, in his presence, he is not considered trustworthy (for he would not say so unless it was true). If he says so outside his presence, he is considered trustworthy (for the other person's statements are considered as slander)." This interpretation fits the Rambam's ruling.
If he says: "So-and-so," his word is accepted26Because we follow the principle that a person will not sin unless he personally benefits (Kiddushin 63b). This, however, is a leniency, granted to the person, because he is a wayfarer [the Rambam's Commentary to the Mishnah (Demai 4:7)]. and [the wayfarer] may purchase [produce] from that person and eat on that basis. If [the wayfarer] went and purchased from that person and asked him: "Who here sells vintage wine?" and the person answers: "The one who sent you," his word is accepted even though it appears that they are in collusion.27And thus could be lying. See parallels in Hilchot Issurei Bi'ah 20:11.

הלכה ח
בַּמֶּה דְּבָרִים אֲמוּרִים בִּזְמַן שֶׁאֵינוֹ מַכִּיר אָדָם שָׁם. אֲבָל אִם מַכִּיר אָדָם שָׁם לֹא יִקַּח אֶלָּא מִן הַמֻּמְחֶה. וְאִם שָׁהָה שָׁם שְׁלֹשִׁים יוֹם אַף עַל פִּי שֶׁאֵינוֹ מַכִּיר אָדָם שָׁם לֹא יִקַּח אֶלָּא מִן הַמֻּמְחֶה:
כסף משנה
8.
When does the above apply? When [the wayfarer] is not familiar with any person in that place.28The Ra'avad qualifies the Rambam's ruling, stating that it applies only when the person he knows is trustworthy. If he is not trustworthy, his recommendation cannot be relied upon. Rav Yosef Korcus states that this is also the Rambam's intent. If, however, he is familiar with people there, he should purchase only from a person [with an established reputation] for observance.29In the present age, this problem is solved by Rabbis and/or institutions giving kashrut certificates that are hung in the respective stores or institutions. If he stays in that place for 30 days, even if he is not familiar with anyone there, he should purchase produce only from an expert.30For after 30 days have passed, the person has had ample time to familiarize himself with the place and there is no need for further leniency. He will certainly have found a place that will offer him hospitality (Radbaz).

הלכה ט
וְלֹא הִתִּירוּ דְּבָרִים אֵלּוּ אֶלָּא בִּתְרוּמוֹת וּמַעַשְׂרוֹת. אֲבָל לְעִנְיַן פֵּרוֹת שְׁבִיעִית אוֹ לְעִנְיַן טָהֳרוֹת לֹא יִקַּח אֶלָּא מִן הַמֻּמְחֶה:
כסף משנה
9.
These leniencies were granted only with regard to terumot and the tithes,31The rationale for the leniency is that the majority of the common people do separate tithes. The laws of demai are merely an additional stringency. but with regard to produce of the Sabbatical year and questions of ritual purity, one should purchase only from a person [with an established reputation] for observance.32For the common people are generally lax in observance of these prohibitions.

הלכה י
הַחַמָּרִין שֶׁנִּכְנְסוּ לָעִיר וְאָמַר אֶחָד מֵהֶן פֵּרוֹת אֵלּוּ אֵינָם מְתֻקָּנִים וּפֵרוֹת חֲבֵרִי מְתֻקָּנִין אֵינוֹ נֶאֱמָן שֶׁמָּא קְנוּנְיָא עָשׂוּ בֵּינֵיהֶן:
כסף משנה
10.
When donkey-drivers33Who bring produce from other places to a city for sale. enter a city and one says: "The appropriate separations have not been made from my produce, but they have been made from my colleague's produce," his word is not accepted. [We fear that] perhaps they are colluding in deception.34The Radbaz asks: Why are we more suspicious here than in the situation mentioned in Halachah 7. In resolution, he explains that people coming to sell their merchandise from another place are more likely to act in collusion than two businessmen in a city.

הלכה יא
הַמּוֹכֵר פֵּרוֹת בְּסוּרְיָא וְאָמַר מִשֶּׁל אֶרֶץ יִשְׂרָאֵל הֵם חַיָּב הַלּוֹקֵחַ לְעַשֵּׂר. מְעֻשָּׂרִין הֵן נֶאֱמָן שֶׁהַפֶּה שֶׁאָסַר הוּא הַפֶּה שֶׁהִתִּיר. מִשֶּׁלִּי הֵן חַיָּב לְעַשֵּׂר. מְעֻשָּׂרִין הֵן נֶאֱמָן שֶׁהַפֶּה שֶׁאָסַר הוּא הַפֶּה שֶׁהִתִּיר. וְאִם יָדוּעַ שֶׁיֵּשׁ לוֹ קַרְקַע בְּסוּרְיָא וְהָיָה רֹב מִמְכָּרוֹ מִשָּׂדֵהוּ חַיָּב הַלּוֹקֵחַ מִמֶּנּוּ לְעַשֵּׂר. שֶׁחֶזְקָתוֹ שֶׁמִּשָּׂדֵהוּ הֱבִיאָם:
כסף משנה
11.
When a person sells produce in Syria35As explained in Hilchot Terumot1:3, the status of Syria is an intermediate level between that of Eretz Yisrael and the Diaspora. There terumah and the tithes have to be separated because of Rabbinic decree, but not because of Scriptural Law. For this reason, our Sages did not enforce the restrictions of demai on such produce [the Rambam's Commentary to the Mishnah (Demai 6:11)]. and says that it comes from Eretz Yisrael,36And was purchased from a common person so that the restrictions associated with demai apply. the purchaser is required to tithe it.37The fact that they have been taken out of Eretz Yisrael is not significant. If he says that it has been tithed, his word is accepted.38And tithing is not required. [The rationale is that] the same person whose words aroused our suspicion also allayed it.39This is a general principle applicable in many areas, both in Jewish business law and with regard to the Torah's prohibitions. When our suspicions are based only on one person's statements, if that person makes a statement that allays those suspicions, we accept it. For our knowledge of the suspicious factor stems from his statements alone; there is no other evidence of such (ibid.). The rationale is that had he desired to lie, he would not have mentioned the factor that arouses the suspicions at the outset.
If he says: "They are mine,"40I.e. "from my field in Syria;" i.e., a place from whose produce tithes must be separated according to Rabbinic decree and he does not say that he tithed the produce. [the purchaser] is obligated to tithe it.41Were he not to have said that they were from his own field, there would be no obligation to tithe the produce, because we would have assume it came from a gentile's field. If he says that it has been tithed, his word is accepted. [The rationale is that] the same statement that aroused our suspicion also allayed it. If it is known that [the seller] owns land in Syria and most [of the produce] he sells is from his own field, one who purchases from him is obligated to tithe,42I.e., even if he does not say specifically that they are his. for we assume that he brought the produce from his own field.

הלכה יב
עֲנִיִּים שֶׁאָמְרוּ פֵּרוֹת אֵלּוּ שֶׁל לֶקֶט שִׁכְחָה וּפֵאָה הֲרֵי אֵלּוּ נֶאֱמָנִין כָּל זְמַן הַגֳּרָנוֹת שֶׁהַלֶּקֶט וְהַשִּׁכְחָה וְהַפֵּאָה מְצוּיִים. וְהוּא שֶׁיִּהְיֶה קָרוֹב מִן הַגֹּרֶן כְּדֵי שֶׁיֵּצֵא וְיָבוֹא בּוֹ בַּיּוֹם. וְאִם אָמְרוּ שֶׁל מַעֲשַׂר עָנִי הֵם הֲרֵי אֵלּוּ נֶאֱמָנִין כָּל הַשָּׁנָה כֻּלָּהּ. וְאֵינָן נֶאֱמָנִין אֶלָּא עַל דָּבָר שֶׁדֶּרֶךְ בְּנֵי אָדָם לִתְּנוֹ:
כסף משנה
12.
When poor people43Even if they are common people whose word is not ordinarily accepted with regard to tithes. say: "This produce is from leket, shichachah, and pe'ah,44Presents given the poor that are exempt from the obligations to tithe (Chapter 2, Halachah 9). their word is accepted as long as there are granaries in which leket, shichachah, and pe'ah can be found and provided [a poor person] is close enough to the granary so that he can go [to it] and return on the same day.
If they said: "They are from the tithes given to the poor,"45In which instance we would assume that the terumot and the first tithe were also separated. their word is accepted throughout those years.46I.e., in the third and sixth years of the seventh year agricultural cycle. The word of these individuals is accepted only with regard to objects which people would ordinarily give [to the poor].

הלכה יג
כֵּיצַד. חִטִּים אֵלּוּ לֶקֶט שִׁכְחָה וּפֵאָה הֵם הֲרֵי אֵלּוּ נֶאֱמָנִים. קֶמַח זֶה שֶׁל לֶקֶט שִׁכְחָה וּפֵאָה הוּא אֵינָם נֶאֱמָנִין. וְאֵין צָרִיךְ לוֹמַר שֶׁאֵין נֶאֱמָנִין עַל הַפַּת לוֹמַר מִמַּתְּנוֹת עֲנִיִּים הוּא אֶלָּא מִתְעַשְּׂרִין דְּמַאי:
כסף משנה
13.
What is implied?47I.e., what is meant by the last statement that the ruling depends on whether it is common for people to give such articles as leket, shichachah, pe'ah, or as tithes to the poor. [Poor people say:] "This wheat is from leket, shichachah, and pe'ah,"48Pe'at HaSadeh states that the Rambam's words are chosen carefully. It is customary to give leket, shichachah, and pe'ah in the field. Hence, it is not likely that they were given as flour. The tithes for the poor, by contrast, are generally given from the home (see Hilchot Matanot Aniyim 6:10). Hence it is possible that flour was given to a poor person in fulfillment of that mitzvah. their word is accepted.49For it is common for people to leave grain as leket, shichachah,and pe'ah, but not to process the grain any further before giving it [the Rambam's Commentary to the Mishnah (Pe'ah 8:3)]. [If they say:] "This flour50I.e., if he says that a homeowner gave him flour, his word is not accepted. If, however, he says that he was given grain and he had it ground into flour himself, his word is accepted. from leket, shichachah, and pe'ah," their word is not accepted.51Because it is not common for a person to have grain ground into flour and then give the flour to the poor. Needless to say, their word is not accepted when they say that bread comes from presents to the poor. Instead, [such articles] should be tithed as demai is.

הלכה יד
נֶאֱמָנִין עַל הַשְּׂעוֹרָה שֶׁל אֹרֶז וְאֵין נֶאֱמָנִין עָלָיו בֵּין חַי בֵּין מְבֻשָּׁל. נֶאֱמָנִין עַל הַפּוֹל וְאֵין נֶאֱמָנִין עַל הַגְּרִיסִין בֵּין חַיִּין בֵּין מְבֻשָּׁלִין. נֶאֱמָנִין עַל הַשֶּׁמֶן לוֹמַר שֶׁל מַעֲשַׂר עָנִי הוּא וְאֵין נֶאֱמָנִין לוֹמַר שֶׁל זֵיתֵי נִקּוּף הֵם. נֶאֱמָנִין עַל הַיָּרָק חַי וְלֹא מְבֻשָּׁל אֶלָּא אִם כֵּן הָיָה דָּבָר מֻעָט. שֶׁכֵּן דֶּרֶךְ בַּעֲלֵי בָּתִּים לִתֵּן מְעַט יָרָק מְבֻשָּׁל מִקְּדֵרָתוֹ לְעָנִי. וּמִתּוֹךְ שֶׁיָּכוֹל לוֹמַר הַבַּעַל הַבַּיִת נְתָנוֹ לִי יָכוֹל לוֹמַר אֲנִי בִּשַּׁלְתִּיו מִמַּתְּנוֹתַי:
כסף משנה
14.
Similarly, their word is accepted with regard to kernels of rice [while in their husks]. Their word is not accepted, however, with regard to husked kernels or cooked ones.52For it was customary for people to give presents from rice while the kernels are still in their husks and not when they have been processed [the Rambam's Commentary to the Mishnah (ibid.)]. Our interpretation of the following clauses is also based on that source. Their word is accepted with regard to beans [in their kernels]. Their word is not accepted, however, with regard to raw, husked beans or cooked beans.
Their word is accepted when they say that oil was from the tithe for the poor. Their word is not accepted, however, if they say it comes from leftover olives.53Which are left for the poor. We do not accept their word in this instance, for it is not common for a sufficient quantity of such olives to be left to make oil. Their word is accepted with regard to raw vegetables, but not with regard to cooked vegetables unless we are speaking about a small quantity. For it is customary for homeowners to give a poor person some vegetables from their pot. And since he can say: "A homeowner gave it to me," he can say: "I cooked it from the presents given me."54I.e., we accept his word based on the principle of miggo; were he to have desired to lie, he could have chosen a more plausible falsehood.

הלכה טו
וְכֵן בֶּן לֵוִי שֶׁאָמַר פֵּרוֹת אֵלּוּ מִמַּעֲשֵׂר רִאשׁוֹן שֶׁנִּטְּלָה תְּרוּמָתוֹ הֵם הֲרֵי זֶה נֶאֱמָן לְעוֹלָם עַל תְּרוּמַת מַעֲשֵׂר כְּשֵׁם שֶׁיִּשְׂרָאֵל נֶאֱמָן עַל תְּרוּמָה גְּדוֹלָה. אֲבָל אֵינוֹ נֶאֱמָן עָלָיו לְפָטְרוֹ מִמַּעֲשֵׂר שֵׁנִי:
כסף משנה
15.
Similarly, the word of a Levite55Even if he is a common person. who says: "This produce is from the first tithe from which terumah was separated" is always56In contrast to leket, shichachah, pe'ah and the tithe for the poor concerning which the poor person's word is accepted only at certain times. accepted with regard to terumat ma'aser,57I.e., the Levite's word is accepted if he says that he separated terumat ma'aser from the tithes that he was given. just as the word of an Israelite is always accepted with regard to the great terumah.58Chapter 9, Halachah 1. In both cases, the transgression is punishable by death at the hand of Heaven. [The Levite's59Unless he is a chavair. word] is not accepted, however, with regard to exempting [the grain] from the second tithe.60I.e., if an Israelite purchases produce from a Levite who is not a chavair and the Levite states that the produce has been tithed and also the second tithe has been separated, the Levites word is not accepted. Although an Israelite's word is accepted regarding the second tithe when we see that he has separated the first tithe (Halachah 5), this does not hold true for a Levite. The rationale is that an Israelite makes a sacrifice when separating the first tithe, but a Levite does not.

הלכה טז
אֵין כָּל הַדְּבָרִים הָאֵלּוּ אֲמוּרִין אֶלָּא בְּעַם הָאָרֶץ שֶׁאֵינוֹ לֹא חָשׁוּד וְלֹא נֶאֱמָן. אֲבָל מִי שֶׁהוּא חָשׁוּד לִמְכֹּר תְּרוּמָה לְשֵׁם חֻלִּין אָסוּר לִקַּח מִמֶּנּוּ כְּלָל דָּבָר שֶׁיֵּשׁ בּוֹ זִקַּת תְּרוּמָה וּמַעֲשֵׂר אֲפִלּוּ קִרְבֵי דָּגִים מִפְּנֵי שֶׁנּוֹתְנִין בָּהֶם שֶׁמֶן. וְאֵין אָסוּר אֶלָּא כָּל שֶׁלְּפָנָיו. אֲבָל אֲצָרוֹ מֻתָּר לִקַּח מִמֶּנּוּ מִפְּנֵי שֶׁהוּא מִתְיָרֵא לְעָרֵב תְּרוּמָה בְּאוֹצָרוֹ שֶׁמָּא יִוָּדַע הַדָּבָר וְיַפְסִיד הַכּל. וְכֵן הֶחָשׁוּד לְמַעֲשֵׂר שֵׁנִי לְמָכְרָן לְשֵׁם חֻלִּין אֵין לוֹקְחִין מִמֶּנּוּ דָּבָר שֶׁיֵּשׁ עָלָיו זִקַּת מַעֲשֵׂר. וְכָל זֶה קְנָס מִדִּבְרֵיהֶם:
כסף משנה
16.
All of the above61I.e., that produce could be purchased from a common person and the separations made afterwards. This concept applies also with regard to the subsequent laws mentioned in this chapter. See similar concepts in Hilchot Shemitah VeYoval 8:14. applies with regard to a common person who is neither suspect [to violate these prohibitions], nor trustworthy [in their observance]. If, however, someone is suspected of selling terumah as ordinary produce, it is forbidden to purchase anything from him that has a connection to terumah and the tithes.62For if terumah was mixed with the produce, the prohibition is much more severe. Even the intestines of fish [may not be purchased from him] because oil is mixed with them.63And we fear that the oil might be terumah or mixed with terumah. It is, however, only forbidden to purchase the produce that is being sold by such a person at that time. It is, by contrast, permitted to purchase from his storehouse, because he will fear to mix terumah into his stores [of produce], lest the matter become known and he lose everything.64I.e., if the Rabbis would discover that such a mixture would be made, they would declare his entire store of produce forbidden.
Similarly, it is forbidden to purchase anything that has a connection to tithes from a person who is suspect of selling the second tithe65That has not been redeemed. as ordinary produce. All of this is a penalty [imposed] by Rabbinic decree.

הלכה יז
חָשׁוּד שֶׁהֵעִיד עַל שֶׁל אֲחֵרִים נֶאֱמָן. חֲזָקָה אֵין אָדָם חוֹטֵא וְלֹא לוֹ. וְאֵין צָרִיךְ לוֹמַר עַם הָאָרֶץ. לְפִיכָךְ עַם הָאָרֶץ שֶׁאָמַר זֶה טֶבֶל וְזֶה תְּרוּמָה זֶה וַדַּאי וְזֶה דְּמַאי אֲפִלּוּ בְּשֶׁלּוֹ נֶאֱמָן. אָמַר אֵלּוּ פֵּרוֹת מְתֻקָּנִין בְּשֶׁל אֲחֵרִים נֶאֱמָן וְהוּא שֶׁלֹּא יֵרָאוּ כְּעוֹשֶׂה קְנוּנְיָא כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
17.
When a person who is suspect to transgress attests [to the tithes being separated from produce] belonging to another person, his word is accepted.66The Ra'avad differs and maintains that the word of a person who is suspect is never accepted even when he testifies with regard to the produce of another person. The Radbaz and the Kessef Mishneh support the Rambam's view. [The rationale is that we operate] under the presumption that a person will not sin without receiving any benefit. Needless to say, this applies with regard to a common person.67For his word is accepted more readily than that of one who is suspect. Therefore, if a common person says: "[This produce] is tevel and this is terumah. This is definitely untithed and this is demai," his word is accepted, even with regard to his own produce.68For in these instances, his statements do not enable ordinary produce to be eaten. If he said: "The required separations have been made from this produce," his word is accepted with regard to the produce of others69But not with regard to his own. provided it does not appear that they are acting in collusion, as we explained.70In Halachah 10.

הלכה יח
הַמּוֹכֵר פֵּרוֹת לַחֲבֵרוֹ וְאַחַר שֶׁיָּצְאוּ מִתַּחַת יָדוֹ אָמַר לַלּוֹקֵחַ פֵּרוֹת שֶׁמָּכַרְתִּי לְךָ טְבָלִים הֵן. הַבָּשָׂר בְּשַׂר בְּכוֹר הָיָה. הַיַּיִן יֵין נֶסֶךְ. שׁוּרַת הַדִּין שֶׁאֵינוֹ נֶאֱמָן אֲפִלּוּ הָיָה הַמּוֹכֵר חָבֵר וְהַזָּרִיז מַחֲמִיר עַל עַצְמוֹ. וְאִם הֶאֱמִינוֹ הֲרֵי זֶה מְשֻׁבָּח אֲפִלּוּ הָיָה הַמּוֹכֵר עַם הָאָרֶץ:
כסף משנה
18.
When a person sells produce to a colleague and, after the produce leaves his hand, he tells the purchaser: "The produce I sold you is tevel. The meat is meat from a firstborn animal.71Which was slaughtered before it was clarified that it possessed a disqualifying blemish. Thus it is forbidden to partake of it and it must be buried. And the wine is wine that was poured as a libation to a false deity.72And is hence, forbidden and must be destroyed. The letter of the law dictates that the seller's word should not be accepted, even if he is a chavair.73I.e., the seller claims that the sale was made in error. He wants to nullify the sale so that he can fulfill the mitzvah of tithing the produce and destroying the forbidden produce. Since the objects have already left the seller's hand, his word is not accepted whether he is a chavair or not. A person who is eager should be stringent with himself. If he accepts his word, [his conduct] is praiseworthy, even if [the seller] is a common person.

זרעים הלכות מעשרות פרק יב
Zeraim Maaser Chapter 12