Kiddushin 65B

אמרינן הן הן עדי יחוד, הן הן עדי ביאה. ובית הלל סברי: אמרינן הן הן עדי יחוד, הן הן עדי ביאה. ומודים ודאי בנתגרשה מן האירוסין, דלא אמרינן הן הן עדי יחוד הן הן עדי ביאה, מפני שאין לבו גס בה.

say: These are the witnesses of seclusion, these are the witnesses of sex. According to Beit Shammai, although there are witnesses that they were secluded, this is not considered to be tantamount to testimony that they had sex. And Beit Hillel hold: We do say that these are the witnesses of seclusion, these are the witnesses of sex. Since it is assumed that they had sex, she is required to obtain a second bill of divorce from him. And Beit Hillel concede to Beit Shammai that certainly in the case of a woman divorced from betrothal, that we do not say that these are the witnesses of seclusion, these are the witnesses of sex, because he is not accustomed to her.

אמר רב יצחק בר שמואל בר מרתא משמיה דרב: המקדש בעד אחד ⁠– אין חוששין לקידושיו, ואפילו שניהם מודים. אמר רבה בר רב הונא: המקדש בעד אחד, בי דינא רבה אמרי: אין חוששין לקידושיו. מאן בי דינא רבה? רב. ואיכא דאמרי: אמר רבה בר רב הונא אמר רב. המקדש בעד אחד, בי דינא רבה אמרי: אין חוששין לקידושיו. מאן בי דינא רבה ⁠– רבי.

Rav Yitzḥak bar Shmuel bar Marta says in the name of Rav: With regard to one who betroths a woman with one witness, one need not be concerned that his betrothal has taken effect, and this is the halakha even if the man and woman both concede that there was a betrothal. Rabba bar Rav Huna says: With regard to one who betroths a woman with one witness, the Great Court says that one need not be concerned that his betrothal has taken effect. The Talmud asks: Who is the Great Court? Rav. And there are those who say a different version of this discussion. Rabba bar Rav Huna said that Rav said: With regard to one who betroths a woman with one witness, the Great Court says that one need not be concerned that his betrothal has taken effect. Who is the Great Court? R' Yehuda HaNasi.