Related על קידושין 8:28

(Devarim 24:1) "If a man take a woman": We are hereby taught that a woman is acquired (as a wife) by money. For (without this verse) it would follow otherwise, viz.: If a Hebrew handmaid, who is not acquired by cohabitation is acquired by money, then a woman, who is acquired by cohabitation, how much more so should she be acquired by money! — (No,) this is refuted by the instance of a yevamah (leviratess), who is acquired by cohabitation, but is not acquired by money. Do not wonder, then, if a woman, who, though she is acquired by cohabitation were not to be acquired by money. It must, therefore, be written "If a man take a woman," to teach that a woman is acquired by money.

"and he cohabit with her." We are hereby taught that a woman is acquired by cohabitation. For (without this verse) it would follow otherwise, viz.: If a yevamah, who is not acquired by money, is acquired by cohabitation, then a woman, who is acquired by money, how much more so should she be acquired by cohabitation! — (No,) this is refuted by the instance of a Hebrew handmaid, who is acquired by money, but is not acquired by cohabitation. Do not wonder, then, if a woman, who, though she is acquired by money, were not to be acquired by cohabitation. It must, therefore, be written "and he cohabit with her," to teach that a woman is acquired by cohabitation.