Makkot 9B

אשת נביא הוא דתיהדר, דלאו נביא לא תיהדר?!

This Talmud questions that response. Is it the wife of a prophet that is returned, and the wife of one who is not a prophet is not returned?

אלא כדאמר רבי שמואל בר נחמני. דאמר רבי שמואל בר נחמני אמר רבי יונתן: הכי קאמר ליה: ״ועתה השב אשת האיש״, מכל מקום. ודקאמרת: ״הגוי גם צדיק תהרג, הלא הוא אמר לי אחותי היא וגו׳״⁠ – נביא הוא וממך למד. אכסנאי (הוא) שבא לעיר, על עסקי אכילה ושתייה שואלין אותו, כלום שואלין אותו ״אשתך זו״ ״אחותך זו״?

Rather, the explanation is as R' Shmuel bar Naḥmani says, as R' Shmuel bar Naḥmani says that R' Yonatan says: This is what God is saying to Abimelech: “And now, restore the man’s wife” (Genesis 20:7), in any case, whether or not he is a prophet. And as for that which you said: “Will You even slay a righteous nation? Didn’t he say to me: She is my sister” (Genesis 20:4–5), claiming that you are a victim of circumstances beyond your control and exempt from punishment, that is not a valid claim. He is a prophet and it is from you that he learned to conduct himself in that manner. With regard to a stranger [akhsenai] who comes to the city, one asks him about matters of eating and drinking, e.g., whether he is hungry or thirsty. Does one ask him: Is that your wife? Is that your sister? Abraham understood from this line of questioning that you are suspect with regard to abducting women, and that is the reason that he introduced Sarah as his sister. Therefore, you are liable to be executed for her abduction.

מכאן שבן נח נהרג, שהיה לו ללמוד ולא למד.

The Talmud comments: From here it is derived that a descendant of Noah, i.e., a non-Jew, is executed for a capital offense even if he says that it is permitted, as he should have learned that it is prohibited and he did not learn.