Halacha

הלכה א
הַתּוֹבֵעַ עֵדָיו לְהָעִיד לוֹ עֵדוּת שֶׁיִּתְחַיֵּב הַנִּתְבָּע בְּעֵדוּתָן לְבַדָּהּ לִתֵּן לְתוֹבֵעַ זֶה מָמוֹן הַמִּטַּלְטֵל. וְכָפְרוּ בְּעֵדוּתָן וְנִשְׁבְּעוּ. בֵּין שֶׁנִּשְׁבְּעוּ בְּבֵית דִּין בֵּין שֶׁנִּשְׁבְּעוּ חוּץ לְבֵית דִּין הֲרֵי אֵלּוּ חַיָּבִין מִשּׁוּם שְׁבוּעַת הָעֵדוּת. שֶׁהֲרֵי הִפְסִידוּהוּ מָמוֹן בִּכְפִירָתָם. וְכֵן אִם הִשְׁבִּיעָם הַתּוֹבֵעַ וְכָפְרוּ בּוֹ אַף עַל פִּי שֶׁלֹּא נִשְׁבְּעוּ הֵן וְלֹא עָנוּ אָמֵן אַחַר שְׁבוּעָתוֹ כֵּיוָן שֶׁכָּפְרוּ הֲרֵי אֵלּוּ חַיָּבִין. וְהוּא שֶׁיַּשְׁבִּיעֵם בְּבֵית דִּין:
כסף משנה
1.
When a plaintiff1This excludes instances when an oath is not made in response to the plaintiff's demands, as stated in Halachah 7. And it excludes an instance when the matter was observed by two pairs of witnesses, as stated in Chapter 10, Halachah 15. demands that witnesses testify concerning a matter that through their testimony alone2This excludes a fine, because in that instance, the defendant does not become liable until he denies the obligation and the witnesses refute his denial. With regard to monetary claims, by contrast, once the witnesses testify, the defendant is liable regardless of whether he admits or disputes his liability. See Halachah 4. will obligate the defendant to pay this plaintiff a financial claim involving moveable property,3Halachah 3 explains that this phrase excludes promissory notes, landed property, and servants. [the witnesses] denied [knowing] testimony and took an oath to this effect - whether in a court of law or outside of it - they are liable for sh'vuat haedut,4This term literally means "the oath [concerning] testimony." As stated in Chapter 1, Halachah 12, a person who takes this oath falsely is liable to bring an adjustable guilt offering. for they caused the plaintiff a financial loss through their denial.
Similarly, if the plaintiff administered an oath to them and they denied the matter, [they are liable] even though they did not take an oath or answer Amen to the oath he [administered]. Since they denied the matter, they are liable, provided he administered the oath to them in court.5As reflected by Halachah 10, when the oath is administered by the plaintiff and the witnesses do not answer Amen, the oath must be administered in court. If, however, the witnesses take the oath on their own accord or they answer Amen, they are liable even if this takes places outside a court, provided the denial takes place within a court, as stated in the following halachah (Radbaz, Kessef Mishneh; see also Chapter 10, Halachah 7 and notes).

הלכה ב
אֵין הָעֵדִים חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת עַד שֶׁיִּכְפְּרוּ בְּעֵדוּתָן בְּבֵית דִּין. בֵּין שֶׁנִּשְׁבְּעוּ אוֹ הִשְׁבִּיעָן בְּבֵית דִּין בֵּין שֶׁנִּשְׁבְּעוּ אוֹ הִשְׁבִּיעָן חוּץ לְבֵית דִּין. וְהַכְּפִירָה בְּבֵית דִּין בִּלְבַד. שֶׁנֶּאֱמַר (ויקרא ה א) "אִם לֹא יַגִּיד וְנָשָׂא עֲוֹנוֹ" מָקוֹם שֶׁיַּגִּיד וְיוֹעִיל הוּא שֶׁאִם לֹא יַגִּיד שָׁם יִתְחַיֵּב:
כסף משנה
2.
The witnesses are not liable for a sh'vuat haedut unless they deny [knowing testimony] in court. Whether they took the oath or the oath was administered to them in court or outside the court, the denial must be in court alone, as [can be derived from Leviticus 5:1]: "If he will not testify, he will bear his sin." [Implied is that] in the place he will testify and [that testimony] will have an effect,6I.e., in court. See Halachah 10 and notes where this concept is discussed. there, if he does not testify, he will be liable.

הלכה ג
תְּבָעָן בְּעֵדוּת שֶׁאֵינָהּ מְחַיֶּבֶת מָמוֹן אוֹ בְּעֵדוּת קַרְקָעוֹת אוֹ עֲבָדִים אוֹ שְׁטָרוֹת וְכָפְרוּ וְנִשְׁבְּעוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת. שֶׁאֵין חַיָּבִין אֶלָּא עַל כְּפִירַת עֵדוּת מָמוֹן שֶׁדּוֹמָה לְפִקָּדוֹן וּתְשׂוּמֶת יָד וְגֵזֶל וַאֲבֵדָה שֶׁפֵּרְטָן הַכָּתוּב בַּפָּרָשָׁה שֶׁהֵן מִטַּלְטְלִין שֶׁגּוּפָן מָמוֹן וּכְשֶׁיָּעִידוּ לָזֶה יִתֵּן זֶה:
כסף משנה
3.
When the plaintiff demands [that the witnesses] testify concerning a claim that does not involve a financial obligation,7E.g., he demanded that they testify that he was a priest or a Levite (Chapter 10, Halachah 3). concerns landed property, servants, or promissory notes, they deny [knowing testimony], and take an oath to that effect, they are not liable for a sh'vuat haedut. For they are liable when denying testimony concerning financial claims that resemble an entrusted object, a [financial] deposit, a robbery, or a lost object which the verse8Leviticus 5:21-22; see the explanations in Chapter 7, Halachah 4, and notes. mentions in this passage. This refers to moveable property which is itself of financial worth9In contrast to promissory notes. that were they to testify on [the plaintiff's] behalf, [the defendant] would have to pay.

הלכה ד
וְכֵן הַמַּשְׁבִּיעַ עֵדֵי קְנָס וְכָפְרוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת. מִפְּנֵי שֶׁאִם קָדַם הַנִּתְבָּע וְהוֹדָה בִּקְנָס יִפָּטֵר מִלְּשַׁלֵּם וְאַף עַל פִּי שֶׁבָּאוּ הָעֵדִים אַחַר כֵּן וְהֵעִידוּ. נִמְצְאוּ הָעֵדִים לֹא חִיְּבוּ זֶה בְּעֵדוּתָן לְבַדָּהּ אֶלָּא עֵדוּתָן עִם כְּפִירַת הַנִּתְבָּע הִיא הַמְחַיֶּבֶת אוֹתָן וְהוֹאִיל וְאִם הוֹדָה לֹא תּוֹעִיל עֵדוּתָן אִם כָּפְרוּ בָּהּ וְנִשְׁבְּעוּ פְּטוּרִין:
כסף משנה
4.
Similarly, when one administers an oath to witnesses who [can testify regarding] a fine and they deny [knowledge] of the matter, they are not liable for a sh'vuat haedut. [The rationale is that] were the defendant to come and acknowledge his liability for the fine first,10See Hilchot Nizkei Mammon 2:8. he would not be liable to pay even though the witnesses came afterwards and testified accordingly. Thus the witnesses did not make him liable through their testimony alone. Instead, it was their testimony together with the denial of the defendant that made him liable. Since their testimony would not be effective if he acknowledged [his liability], if they denied [knowing of] the matter and took an oath, they are not liable.

הלכה ה
מַשְׁבִּיעֲכֶם אֲנִי שֶׁתָּבוֹאוּ וְתָעִידוּ לִי שֶׁיֵּשׁ לִי בְּיַד פְּלוֹנִי תַּשְׁלוּמֵי כֶּפֶל וְתַשְׁלוּמֵי אַרְבָּעָה וַחֲמִשָּׁה וְכָפְרוּ. חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת מִפְּנֵי הַקֶּרֶן שֶׁהוּא מָמוֹן לֹא מִפְּנֵי הַכֶּפֶל שֶׁהוּא קְנָס. וְכֵן אִם הִשְׁבִּיעָם שֶׁיָּעִידוּ לוֹ שֶׁאָנַס פְּלוֹנִי אוֹ פִּתָּה בִּתּוֹ וְכָפְרוּ חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת מִפְּנֵי הַבֹּשֶׁת וְהַפְּגָם שֶׁאִם הוֹדָה בָּהֶם הַנִּתְבָּע מְשַׁלֵּם לֹא מִפְּנֵי הַקְּנָס. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
5.
[When a plaintiff administers an oath to witnesses, saying:] "I am making you take an oath that you come and testify on my behalf that so-and-so owes me a double payment"11For a theft. or a four- or five-fold payment12For the theft and slaughter or sale of a sheep or a cow. and the witnesses deny [knowledge of the matter], they are liable for a sh'vuat haedut because of the principal which is a financial obligation,13For this must be paid even if he admits stealing himself. but not because of the double payment which is a fine.
Similarly, if he administered an oath that they testify that so-and-so raped or seduced his daughter and they deny [knowledge of the matter], they are liable for a sh'vuat haedut because of the [payment due] for embarrassment and damages.14See Chapter 8, Halachah 3, and notes. For if the defendant acknowledged his obligation, he would have to pay these obligations, but not because of the fine. Similar laws apply in all analogous situations.

הלכה ו
אֵין הָעֵדִים חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת עַד שֶׁיִּכְפְּרוּ וְיִשָּׁבְעוּ אַחַר תְּבִיעַת בַּעַל דִּין עַצְמוֹ אוֹ שְׁלוּחוֹ. אֲבָל אִם קָדְמוּ וְנִשְׁבְּעוּ קֹדֶם שֶׁיִּתְבָּעֵם פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת:
כסף משנה
6.
Witnesses are not liable for a sh'vuat haedut until they deny [knowledge of the matter] and take an oath after the plaintiff or his agent15This applies to a person who has been given power of attorney (see Chapter 7, Halachah 6). If he has not been given formal power of attorney, even if he is an agent acting on behalf of the principal, the oath he administers is not of consequence (Rabbi Akiva Eiger). demand [that they testify]. If, however, they take an oath first, before a demand is made of them, they are not liable for a sh'vuat haedut.

הלכה ז
כֵּיצַד. רָאוּ הַתּוֹבֵעַ הוֹלֵךְ אַחֲרֵיהֶן אָמְרוּ לוֹ לָמָּה אַתָּה בָּא אַחֲרֵינוּ שְׁבוּעָה שֶׁאֵין אָנוּ יוֹדְעִין לְךָ עֵדוּת הֲרֵי אֵלּוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת מִפְּנֵי שֶׁלֹּא תְּבָעָן הַתּוֹבֵעַ אֶלָּא הֵם קָדְמוּ וְנִשְׁבְּעוּ בִּתְבִיעַת עַצְמָן. וְכֵן אִם הִשְׁבִּיעָם הַנִּתְבָּע שֶׁאִם תֵּדְעוּ לָזֶה שֶׁתּוֹבֵעַ אוֹתוֹ עֵדוּת שֶׁתָּבוֹאוּ וְתָעִידוּ לוֹ וְכָפְרוּ הֲרֵי אֵלּוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת עַד שֶׁיַּשְׁבִּיעֵם הַתּוֹבֵעַ. וְאֵין צָרִיךְ לוֹמַר אִם הִשְׁבִּיעָם שֶׁיָּבוֹאוּ וְיָעִידוּ שֶׁיֵּשׁ לִפְלוֹנִי בְּיַד פְּלוֹנִי מָמוֹן וְכָפְרוּ שֶׁהֵן פְּטוּרִין שֶׁאֵין זֶה הַתּוֹבֵעַ בַּעַל דִּין עַצְמוֹ. וְכֵן אִם קָדְמָה שְׁבוּעָה לָעֵדוּת הֲרֵי אֵלּוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת שֶׁנֶּאֱמַר (ויקרא ה א) "וְשָׁמְעָה קוֹל אָלָה וְהוּא עֵד". שֶׁקָּדְמָה עֵדוּת לִשְׁבוּעָה לֹא שֶׁקָּדְמָה שְׁבוּעָה לְעֵדוּת:
כסף משנה
7.
What is implied? [The witnesses] saw the plaintiff following after them, they told him: "Why are you following us? We are taking an oath that we do not know any testimony involving you," they are not liable for a sh'vuat haedut. [The rationale is that] the plaintiff did not make a demand of them. Instead, they took the oath first on their own initiative.16As the Rambam writes in his Commentary to Mishnah (Sh'vuot 4:12), Leviticus 5:1 states "If he does not tell" but the word "not" is written lamed alef vav. This implies both lamed alef "not," and lamed vav "to him." Implied is that he must say no to him, i.e., in response to his demand.
Similarly, if the defendant administered an oath to them that if they knew testimony involving the plaintiff they should come and testify and they deny [knowledge of the matter], they are not liable for a sh'vuat haedut unless the plaintiff makes them take the oath.17This can also be derived through the process of exegesis mentioned above. One can infer that when the witnesses refuse to testify, they must speak to the plaintiff himself. Needless to say, if he administered an oath that they should come to testify that so-and-so owes so-and-so money and they deny [knowledge of the matter], they are not liable. For the person making this demand is not the plaintiff himself. Similarly, if the oath preceded [their knowledge of] the testimony, they are not liable for a sh'vuat haedut, as [implied by Leviticus 5:1]: "And he heard the voice of an oath [when] he was a witness." [It can be inferred that knowledge of] the testimony preceded the oath and not that the oath preceded the knowledge of the testimony.

הלכה ח
כֵּיצַד. מַשְׁבִּיעַ אֲנִי עֲלֵיכֶם כְּשֶׁתֵּדְעוּ לִי עֵדוּת שֶׁתָּבוֹאוּ וּתְעִידוּנִי וְאָמְרוּ אָמֵן וְיָדְעוּ לוֹ עֵדוּת אַחַר כֵּן וּתְבָעָם לְהָעִיד וְכָפְרוּ בּוֹ הֲרֵי אֵלּוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת:
כסף משנה
8.
What is implied? [The plaintiff says:] "I am administering to you an oath that if you will know of testimony concerning me that you come and testify," and the witnesses responded Amen and afterwards they observed a matter concerning him.18I.e., at the time the oath was administered, they did not have knowledge of testimony concerning the plaintiff, but afterwards they observed the matter under investigation. If he demands that they testify and they deny [knowledge of the matter], they are not liable for a sh'vuat haedut.

הלכה ט
אֵין הָעֵדִים חַיָּבִים בִּשְׁבוּעַת הָעֵדוּת עַד שֶׁיְּיַחֵד אוֹתָם הַתּוֹבֵעַ וְיַשְׁבִּיעֵם אוֹ יִשָּׁבְעוּ. כֵּיצַד. עָמַד בְּבֵית הַכְּנֶסֶת וְאָמַר מַשְׁבִּיעַ אֲנִי כָּל מִי שֶׁיֵּדַע לִי עֵדוּת שֶׁיָּבוֹא וְיָעִיד לִי וְעָנוּ כֻּלָּם אָמֵן וְעֵדָיו בִּכְלָלָם וְאַחַר כָּךְ תָּבַע עֵדָיו וְכָפְרוּ בּוֹ הֲרֵי אֵלּוּ פְּטוּרִין מִשְּׁבוּעַת הָעֵדוּת. מִפְּנֵי שֶׁלֹּא יִחֵד עֵדָיו בִּשְׁבוּעָה בִּפְנֵי עַצְמָן. אֲבָל אִם אָמַר מַשְׁבִּיעַ אֲנִי כָּל הָעוֹמְדִים כָּאן שֶׁאִם יֵדְעוּ לִי עֵדוּת שֶׁיָּבוֹאוּ וְיָעִידוּ לִי וְהָיוּ עֵדָיו בִּכְלָלָם וְכָפְרוּ הֲרֵי אֵלּוּ חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת שֶׁהֲרֵי יִחֲדָם בִּכְלַל אֲחֵרִים:
כסף משנה
9.
Witnesses are not liable for a sh'vuat haedut until the plaintiff singles them out and administers an oath to them or they take an oath.19From the exegesis of the prooftext cited above, Sh'vuot 35a understands that the verse is speaking, not of people in general, but of persons singled out to serve as witnesses.
What is implied? A person stood up in a synagogue and said: "I am administering an oath to anyone who knows testimony concerning me to come and testify on my behalf." They all - including his witnesses - responded Amen. Afterwards, he demanded of his witnesses that they testify and they denied [knowledge of the matter]. They are not liable for a sh'vuat haedut, because he did not single out the witnesses individually. If, however, he said: "I am administering an oath to all of those standing here that if they know testimony concerning me to come and testify on my behalf." [If] his witnesses were among those present and [then] they denied [knowledge of the matter], they are liable for a sh'vuat haedut, because he singled them out among the others.20Although he spoke to the group as a whole, the oath was directed to each of the persons individually.
Rabbenu Nissim mentions another concept related to this ruling. A plaintiff may administer an oath to a person even when he is not certain that the person in fact knows testimony concerning him.

הלכה י
וְכֵן אִם אָמַר לָעֵדִים בּוֹאוּ וְהָעִידוּ לִי שֶׁיֵּשׁ לִי מָנֶה בְּיַד פְּלוֹנִי. וְאַחַר כָּךְ עָמַד בְּבֵית הַכְּנֶסֶת וְהִשְׁבִּיעַ כָּל מִי שֶׁיּוֹדֵעַ לוֹ עֵדוּת יָבוֹא וְיָעִיד וְלֹא בָּאוּ וְלֹא הֵעִידוּ הֲרֵי אֵלּוּ חַיָּבִין. שֶׁהֲרֵי תְּבָעָן תְּחִלָּה. וְהוּא שֶׁיִּהְיוּ אָז בְּבֵית הַכְּנֶסֶת וְיִהְיֶה שָׁם בֵּית דִּין. אֲבָל אִם לֹא הָיוּ בִּפְנֵי בֵּית דִּין אִם עָנוּ אָמֵן חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת כְּשֶׁיִּכְפְּרוּ בְּעֵדוּתָן בְּבֵית דִּין וְאִם לֹא עָנוּ אָמֵן אֵינָן חַיָּבִין:
כסף משנה
10.
Similarly, if he told the witnesses: "Come and testify on my behalf that so-and-so owes me a maneh" and then stands in a synagogue and said: "I am administering an oath to anyone who knows testimony concerning me to come and testify on my behalf," should they not come and testify, they are liable, because he made a demand of them previously. [This applies] provided they are present in the synagogue and a court is also there.21Since they did not take the oath or answer Amen, they are not liable unless the oath is administered in the presence of a court, as stated in Halachah 1. If a court was not present, they are liable for a sh'vuat haedut if they answered Amen and deny [knowledge of the matter] while in a court of law.22For their denial must be made in a court of law, as stated in Halachah 2.
The Ra'avad differs with the Rambam's decision, explaining that the Rambam follows the opinion of Rabbi Meir (Sh'vuot 30a), but the Ra'avad maintains that the halachah should be decided according to the Sages who differ with rabbi Meir. Similarly, the Ra'avad also differs with the Rambam's postulate that if the witnesses do not answer Amen, the oath must be administered in a court.
The Radbaz justifies the Rambam's position, explaining that since the witnesses did not take the oath themselves or respond Amen, it is their denial of knowledge of the testimony that constitutes acceptance of the oath. Accordingly, just as the denial must be made in court, the oath must be administered in court. For it is inappropriate that the oath itself be administered outside the court, while its acceptance is required to be in court. See also Chapter 10, Halachah 17 and notes.
If they did not answer Amen, they are not liable.

הלכה יא
אֶחָד הַמַּשְׁבִּיעַ עֵדָיו בִּשְׁבוּעָה. אוֹ שֶׁאָמַר לָהֶן מְצַוֶּה אֲנִי עֲלֵיכֶם בִּשְׁבוּעָה אוֹסֶרְכֶם אֲנִי בִּשְׁבוּעָה הֲרֵי אֵלּוּ חַיָּבִין. וְהוּא שֶׁיַּשְׁבִּיעֵם בְּשֵׁם אוֹ בְּכִנּוּי מִן הַכִּנּוּיִים כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
11.
Whether one administers an oath to his witnesses or tells them "I am commanding you with an oath" or "I am binding you with an oath," they are liable provided he administers the oath23Or includes God's name in any of the other expressions (Radbaz). with God's name or with one of the terms used to describe Him as explained.24See Chapter 2, Halachot 2-4.

הלכה יב
וְאֵין הָעֵדִים חַיָּבִין עַד שֶׁיַּשְׁבִּיעֵם בְּלָשׁוֹן שֶׁהֵם מַכִּירִין אוֹתָהּ:
כסף משנה
12.
The witnesses are not liable unless the oath is administered to them in a language that they understand.25See Chapter 7, Halachah 7. This applies even if they answer Amen to the oath (Jerusalem Talmud, Sotah 7:1).

הלכה יג
הִנֵּה לָמַדְתָּ שֶׁאֵין הָעֵדִים חַיָּבִין בִּשְׁבוּעַת הָעֵדוּת אֶלָּא עַל פִּי עֲשָׂרָה דְּבָרִים. וְאֵלּוּ הֵן. שֶׁיִּתְבָּעֵם הַתּוֹבֵעַ. וְשֶׁתִּהְיֶה עֵדוּת מָמוֹן. וְשֶׁיִּהְיֶה מָמוֹן הַמִּטַּלְטֵל. וְשֶׁיִּתְחַיֵּב הַנִּתְבָּע לְשַׁלֵּם בְּעֵדוּתָן לְבַד אִם הֵעִידוּ. וְשֶׁיִּכְפְּרוּ אַחַר שֶׁתְּבָעָן הַתּוֹבֵעַ. וְשֶׁיִּכְפְּרוּ בְּבֵית דִּין. וְשֶׁתִּהְיֶה שָׁם שְׁבוּעָה בְּשֵׁם אוֹ בְּכִנּוּי. וְשֶׁתִּקְדַּם יְדִיעַת הָעֵדוּת לַשְּׁבוּעָה. וְשֶׁיְּיַחֵד עֵדָיו בְּעֵת הַשְּׁבוּעָה אוֹ בְּעֵת הַתְּבִיעָה. וְשֶׁתִּהְיֶה הַשְּׁבוּעָה בְּלָשׁוֹן שֶׁהֵן מַכִּירִין אוֹתָהּ:
כסף משנה
13.
Thus you have learned that witnesses are not liable for a sh'vuat haedut unless ten conditions are [met]. They are:26All of these points have been discussed in the previous halachot.
a) [The witnesses] must be charged [with testifying] by the plaintiff;
b) [The matter] must involve a financial claim;
c) It must involve movable property;
d) Their testimony alone, had it been given, would be sufficient to require the defendant to pay;
e) They must deny [knowledge of the matter] after the plaintiff charges them;
f) They must issue their denial in court;
g) God's name or a term used to describe Him must be mentioned in the oath;
h) The knowledge of the matter must precede the oath;
i) The witnesses must be singled out at the time of the oath or at the time they are charged;
j) The oath must be in a language that they understand.

הלכה יד
כָּל מָקוֹם שֶׁאָמַרְנוּ פָּטוּר. פָּטוּר מִשְּׁבוּעַת הָעֵדוּת אֲבָל חַיָּב בִּשְׁבוּעַת בִּטּוּי וְהוּא שֶׁנִּשְׁבַּע אוֹ שֶׁעָנָה אָמֵן אִם הִשְׁבִּיעוֹ אַחֵר שֶׁהֲרֵי נִשְׁבַּע עַל שֶׁקֶר. אֲבָל הַמְחֻיָּב בִּשְׁבוּעַת הָעֵדוּת אַף עַל פִּי שֶׁהוּא נִשְׁבַּע עַל שֶׁקֶר וְאַף עַל פִּי שֶׁהוּא מֵזִיד אֵינוֹ חַיָּב מִשּׁוּם שְׁבוּעַת בִּטּוּי אֶלָּא מִשּׁוּם שְׁבוּעַת הָעֵדוּת בִּלְבַד. שֶׁהֲרֵי הַכָּתוּב הוֹצִיא שְׁבוּעַת הָעֵדוּת מִכְּלַל שְׁבוּעַת בִּטּוּי לְחַיֵּב הַמֵּזִיד בָּהּ כְּשׁוֹגֵג בְּקָרְבָּן אֲבָל לֹא בְּמַלְקוֹת שֶׁנֶּאֱמַר (ויקרא ה ד ה) "לְאַחַת מֵאֵלֶּה". בְּמִין אֶחָד מִמִּינֵי שְׁבוּעוֹת אַתָּה מְחַיֵּב הַנִּשְׁבָּע וְאִי אַתָּה מְחַיְּבוֹ בִּשְׁנֵי מִינִין עַד שֶׁיִּהְיֶה חַיָּב בְּדִין שְׁבוּעַת הָעֵדוּת וּבְדִין שְׁבוּעַת בִּטּוּי:
כסף משנה
14.
Whenever we have used the expression "they are not liable" [in this chapter], the intent is that they are not liable for a sh'vuat haedut. They are, however, liable for a sh'vuat bitui, provided they take the oath or answer Amen to an oath administered by a colleague, because they took a false oath.27Although the Rambam's position is shared by many other Rishonim, there are others (e.g., Rashi, Sh'vuot 25b), who differ and maintain that since the oath involves testimony, one is never liable for a sh'vuat bitui even when he is not liable for a sh'vuat haedut. See Halachah 18 and notes.
When, by contrast, one is liable for a sh'vuat haedut, he is only liable for a sh'vuat haedut and is not liable for a sh'vuat bitui, even though he took a false oath and did so intentionally. [The rationale is that] the Torah removed a sh'vuat haedut from the category of sh'vuat bitui to make a person who deliberately [takes a false oath] liable for a sacrifice for its violation just as one who took it inadvertently.28Sh'vuot 30a notes that with regard to all the other types of oaths, the Torah uses the expression "and it became concealed from him," but it does not use that expression with regard to a sh'vuat haedut. Implied is that even if the matter is not concealed, i.e., he transgresses deliberately, he is liable for a sacrifice. The Radbaz questions - without resolving - why the Torah gives the person a lesser punishment - a sacrifice - instead of lashes, when he purposefully violates this transgression. He is not, however, liable for lashes, as [can be derived from Leviticus 5:5 which] states: "For one of these."29The same passage mentions both a sh'vuat haedut and a sh'vuat bitui. This verse teaches that one can be held liable for only one of these types of oaths. This also applies with regard to the other false oaths for which the Torah holds one liable. One can be held liable only for one. A person who takes a [false] oath is liable for one type of oath, but not two. [We do not hold him liable for both] a sh'vuat haedut and a sh'vuat bitui.

הלכה טו
מַשְׁבִּיעַ אֲנִי עֲלֵיכֶם אִם לֹא תָּבוֹאוּ וְתָעִידוּ לִי שֶׁיֵּשׁ לִי בְּיַד פְּלוֹנִי פִּקָּדוֹן וּתְשׂוּמֶת יָד גֵּזֶל וַאֲבֵדָה. שְׁבוּעָה שֶׁאֵין אָנוּ יוֹדְעִין לְךָ עֵדוּת אֵינָן חַיָּבִין אֶלָּא אַחַת. שְׁבוּעָה שֶׁאֵין אָנוּ יוֹדְעִין לְךָ עֵדוּת שֶׁיֵּשׁ לְךָ בְּיַד פְּלוֹנִי פִּקָּדוֹן וּתְשׂוּמֶת יָד גֵּזֶל וַאֲבֵדָה חַיָּבִין עַל כָּל אַחַת וְאַחַת:
כסף משנה
15.
[When the plaintiff says: "I am administering] an oath to you unless you come and testify that so-and-so has an entrusted object, a [financial] deposit, stolen property, and a lost object of mine in his possession," [and the witnesses respond: "We are taking] an oath that we do not know of any testimony concerning you," they are liable for only one [sacrifice].30Because they included all the obligations in a single statement. Note the parallel to this and the subsequent laws in Chapter 7, Halachot 10-14. [If they say: "We are taking] an oath that we do not know of any testimony concerning an entrusted object, a [financial] deposit, stolen property, and a lost object of yours in so-and-so's possession, they are liable for each [statement].31For they singled out each object individually.

הלכה טז
מַשְׁבִּיעַ אֲנִי עֲלֵיכֶם אִם לֹא תָּבוֹאוּ וְתָעִידוּ לִי שֶׁיֵּשׁ לִי בְּיַד פְּלוֹנִי חִטִּים וּשְׂעוֹרִים וְכֻסְּמִין. שְׁבוּעָה שֶׁאֵין אָנוּ יוֹדְעִין לְךָ עֵדוּת אֵינָם חַיָּבִין אֶלָּא אַחַת. שְׁבוּעָה שֶׁאֵין אָנוּ יוֹדְעִים לְךָ עֵדוּת שֶׁיֵּשׁ לְךָ בְּיַד פְּלוֹנִי חִטִּים וּשְׂעוֹרִים וְכֻסְּמִין חַיָּבִין עַל כָּל אַחַת וְאַחַת:
כסף משנה
16.
[When the plaintiff says: "I am administering] an oath to you unless you come and testify that so-and-so has wheat, barley, and buckwheat of mine in his possession," and [the defendant responds]: "[We are taking] an oath that we do not know of any testimony concerning you," they are liable for only one [sacrifice].32Although they are different species of grain, since he included them all in one statement, he is liable only once. [If they answer: "We are taking] an oath that we do not know of any testimony concerning any wheat, barley, and buckwheat of yours in his possession," he is liable for each [statement].

הלכה יז
וְכֵן אִם תָּבְעוּ אוֹתָן רַבִּים לְהָעִיד לָהֶם וְאָמְרוּ שְׁבוּעָה שֶׁאֵין אָנוּ יוֹדְעִין לָכֶם עֵדוּת אֵינָן חַיָּבִין אֶלָּא אַחַת. לֹא לְךָ וְלֹא לְךָ וְלֹא לְךָ חַיָּבִין עַל כָּל אַחַת וְאַחַת כְּדֶרֶךְ שֶׁבֵּאַרְנוּ בִּשְׁבוּעוֹת הַפִּקָּדוֹן:
כסף משנה
17.
Similarly, if many people charged them with testifying and they said: "[We are taking] an oath that we do not know of any testimony concerning you," they are liable for only one [sacrifice]. [If they said:] "...concerning you, and you, and you," they are liable for each [statement], as explained with regard to sh'vuat hapikadon.33Because they included all the obligations in a single statement. Note the parallel to this and the subsequent laws in Chapter 7, Halachot 10-14.

הלכה יח
הַנִּשְׁבָּע לַחֲבֵרוֹ שֶׁהוּא יוֹדֵעַ לוֹ עֵדוּת וְנִמְצָא שֶׁאֵינוֹ יוֹדֵעַ לוֹ עֵדוּת הֲרֵי זֶה פָּטוּר וְאֵין כָּאן לֹא שְׁבוּעַת הָעֵדוּת וְלֹא שְׁבוּעַת בִּטּוּי. מִפְּנֵי שֶׁשְּׁבוּעַת בִּטּוּי אֵינָהּ אֶלָּא בְּדָבָר שֶׁיֵּשׁ בּוֹ לָאו וְהֵן. וְאִם יֹאמַר שְׁבוּעָה שֶׁאֵינִי יוֹדֵעַ לְךָ עֵדוּת אֵין זֶה שְׁבוּעַת בִּטּוּי אֶלָּא שְׁבוּעַת הָעֵדוּת. הוֹאִיל וְלָאו זֶה שֶׁיֵּשׁ בָּהּ אֵינָהּ שְׁבוּעַת בִּטּוּי. כָּךְ הֵן שֶׁבָּהּ שֶׁהוּא הַנִּשְׁבָּע שֶׁיּוֹדֵעַ לוֹ עֵדוּת אֵינוֹ שְׁבוּעַת בִּטּוּי:
כסף משנה
18.
When a person administers an oath to a colleague that he knows testimony concerning him and ultimately, it is discovered that he does not know testimony, [the colleague] is not liable, neither for a sh'vuat haedut34For a sh'vuat haedut involves a situation when the witnesses refuse to testify., nor for a sh'vuat bitui. [The rationale is that] a sh'vuat bitui involves only matters that have both a positive and negative dimension.35See Chapter 1, Halachah 1, and notes. Were the person to have said: "I am taking an oath that I do not know testimony concerning you," that would not be a sh'vuat bitui, but instead a sh'vuat haedut. Hence since the negative dimension of the statement is not a sh'vuat bitui, the positive dimension, taking an oath that one knows testimony, is not a sh'vuat bitui.36Hence he is totally absolved from liability.
The Kessef Mishneh notes that one could raise a question based on Sh'vuat 25b. From that passage, it would appear that this and the concept stated in Halachah 14 are conflicting positions and one cannot accept both as halachah. Nevertheless, he explains that it is only in the preliminary stage of the Talmud's argument that the positions appear conflicting. After the Talmud cites the teaching derived from the prooftext, "for one of these," the two rulings can be reconciled. He cites other Rishonim who interpret the passage in this manner.

הלכה יט
דָּבָר בָּרוּר הוּא שֶׁהַנִּשְׁבָּע לַחֲבֵרוֹ שֶׁהֵעִיד לוֹ וְהוּא לֹא הֵעִיד אוֹ שֶׁלֹּא הֵעִיד לוֹ וְהוּא הֵעִיד הֲרֵי זֶה חַיָּב מִשּׁוּם שְׁבוּעַת בִּטּוּי וְאֵין כָּאן שְׁבוּעַת עֵדוּת כְּלָל:
כסף משנה
19.
It is clear that when a person takes an oath to a colleague that he testified on his behalf and he did not testify or that he did not testify and he testified, he is liable for a sh'vuat bitui;37For he is taking an oath regard a specific activity which he performed or did not perform in the past. Since it has both a positive and negative dimension, he is liable. The fact that this oath does not have a future dimension - for if one takes an oath that he will not testify, he is negating a mitzvah, and hence, it is an oath in vain (Chapter 5, Halachah 15) and not a sh'vuat bitui - does not prevent one from being liable for the oath referring to the past. there is no connection to a sh'vuat haedut at all.38For a sh'vuat haedut involves only the future.

הפלאה הלכות שבועות פרק ט
Haflaah Shevuos Chapter 9