Makkot 15A

אמרו לו: אמרת? אמר להו: לא. אמר רבה: האלהים! אמרה, וכתיבא ותנינא: כתיבא ⁠– ״וישלחו מן המחנה [וגו׳]״ ״ולא יטמאו את מחניהם״. תנינא ⁠– הבא למקדש טמא.

They said to R' Yoḥanan: Did you say this halakha? R' Yoḥanan said to them: No. Rabba bar bar Ḥana said in the form of an oath: By God, he said it, and this halakha is written in the Torah and we learn it in the Mishnah. It is written: “And they should send from the camp any man who is leprous, and any zav…and they should not render their camp impure” (Numbers 5:2–4). There is a prohibition against rendering the camp impure, and there is a positive mitzva to send them out of the camp. Since the positive mitzva precedes and is independent of the prohibition, one is flogged for the violation of that prohibition, as we learn in the Mishnah among those liable to receive lashes: One who entered the Temple while ritually impure.

אלא מאי טעמא קא הדר ביה? משום דקשיא ליה אונס. דתניא: אונס שגירש, אם ישראל הוא ⁠– מחזיר ואינו לוקה. אם כהן הוא ⁠– לוקה ואינו מחזיר.

The Talmud asks: Rather, what is the reason he retracted his statement and claimed he did not say it? The Talmud answers: It is due to the fact that the halakha concerning one who rapes a virgin young woman, who is required by Torah law to marry her and for whom it is prohibited to divorce her as long as he lives, is difficult for him, as it is taught in a baraita: In the case of a rapist who divorced the woman he raped, if he is a non-priest, he remarries her, and he is not flogged for violating the prohibition: “He may not send her away all his days” (Deuteronomy 22:29). If he is a priest, he is flogged for violating the prohibition, and he does not remarry her because it is prohibited for him to marry a divorcée.