Дварим 24:2 Комментарий: Rashi, Chizkuni, Ibn Ezra & Siftei Chakhamim

לאיש אחר [AND WHEN SHE IS GONE OUT OF HIS HOUSE, AND HATH GONE AND BECOME] “ANOTHER” MAN’S WIFE — He is “another” (a different) man, not one of a pair with the first: he turned the wicked woman out of his house, whilst this man hath taken her into his house (Gittin 90b).

והלכה והיתה לאיש אחר, “and she goes and has become someone else’s wife;” the wording implies that even if she had only become betrothed to another man and had not yet consummated this bond, her former husband must on no account take her back as his wife. The sages derive this from the passive: והיתה, “she has become some other man’s.” If, after having been divorced, this woman had engaged in sexual relationships with another man without having a legal marriage with him, even if she had been paid as a harlot for such a relationship, her former husband is allowed to remarry her. If that woman had been divorced because she had been guilty of adultery, her husband cannot remarry her even if she had not remarried or had not been intimate with any other man.

having left never to return. Moreover, it must be publicly known that she has ceased being a member of his household.