A man who does not live in the same house as his wife for any reason, yet remains married to her, must continue to fulfill his obligations to her: upkeep and sex. The husband who lives outside his wife’s home must give his wife money and be with her at least once a week, on the night of the Sabbath; as the early sages put it, “He must give her each week a silver ma’ah and she is to eat with him every Sabbath.” One of the scholars, Rav Nachman, explained that it follows the plain meaning — he must eat with her from Friday night to Saturday night. Another scholar, Rav Ashi, interpreted the word eat to mean a man must have sex with his wife on the Sabbath. The scholars asked how he derived sex from the word eat. From the verse in Proverbs: “This is the way of an adulterous woman: She eats and wipes her mouth, and says, ‘I have done no wickedness'” (Proverbs 30:20), meaning that the adulterous woman has sexual intercourse, cleans herself up, and claims she did not commit adultery. This shows that eating, in the Scriptures, means sex. The scholars then asked: According to the early sage Rabban Shimon son of Gamliel, the husband not only must “eat” with her on Friday night, but also on the Sabbath day. If the early sage means eating as sex, how do we reconcile this with the prohibition against having sexual relations in daylight, lest the man see something loathsome about his wife and be repulsed? Answer: In a darkened house a couple may have relations during the day as well.
(Babylonian Talmud, Tractate Ketubot 64b-65b)