Ketubot 22B

אמתלא לדבריה ⁠— נאמנת. תנא מיניה ארבעים זימנין, ואפילו הכי לא עבד שמואל עובדא בנפשיה.

rationale for her statement, she is deemed credible. The Talmud relates: Shmuel learned this halakha from him 40 times to ensure that he would not forget it, and even so, when confronted with a similar situation, Shmuel did not rely on that lenient ruling and did not take action with regard to himself and his wife.

תנו רבנן: שנים אומרים ״מת״, ושנים אומרים ״לא מת״. שנים אומרים ״נתגרשה״, ושנים אומרים ״לא נתגרשה״⁠ — הרי זו לא תנשא, ואם נשאת ⁠— לא תצא. רבי מנחם בר יוסי אומר: תצא. אמר רבי מנחם בר יוסי: אימתי אני אומר תצא, בזמן שבאו עדים, ואחר כך נשאת. אבל נשאת ואחר כך באו עדים ⁠— לא תצא.

§ A baraita states that if two witnesses say: The husband died, and two witnesses say: He did not die; or if two witnesses say: This woman was divorced, and two witnesses say: She was not divorced, this woman may not remarry as there is no unequivocal testimony that she is unmarried. And if she remarried, she need not leave her husband. R' Menaḥem bar Yosei says: She must leave her husband. And R' Menaḥem bar Yosei said: When do I say that she must leave her husband? It is in a case where witnesses came to testify that she is still married and she remarried after that. However, if she remarried and the witnesses came after that, she need not leave her husband based on the uncertainty created by contradictory witnesses.

מכדי תרי ותרי נינהו, הבא עליה באשם תלוי קאי! אמר רב ששת: כגון שנשאת לאחד מעדיה. היא גופה באשם תלוי קיימא! באומרת: ״ברי לי״.

The Talmud asks: After all, they are two witnesses testifying that she is married and two witnesses testifying that she is not; how then can the ruling be that after remarrying she need not leave her husband? In that case, one who has sex with her stands liable to bring a guilt-offering for uncertainty. For any prohibition whose certain violation renders one liable to bring a sin-offering, its uncertain violation renders one liable to bring a guilt-offering for uncertainty. Rav Sheshet said: This is a case where she married one of her witnesses who testified that she is unmarried. As far as he is concerned, there is no uncertainty. The Talmud asks: She herself stands liable to bring a guilt-offering for uncertainty, as she has no independent knowledge whether her husband died. The Talmud answers that this is a case where she says: It is clear to me that he died.