Maimonides’ discussion of the laws of the sotah, a married woman suspected of idolatry, starts as follows (MT Hilkhot Sotah 1:1): “The jealousy that the Torah speaks of, ‘and he became jealous of his wife,’ is when he says to her before witnesses ‘do not seclude yourself with so-and-so’…”
Oddly, the first Torah verse quoted in this legal code is not the first Torah verse in the section describing the laws of the sotah. That section begins as follows (Numbers 5:11–14):
The Eternal said to Moses: Speak to the Israelites, and tell them: Whenever a man’s wife goes astray and defiles with an act of defilement—that is, a man had sexual intercourse with her, and it was hidden from her husband, and they were in secret, and she became impure, and there was no witness with her, and she was not raped—and a spirit of jealousy came over him, and he became jealous of his wife, and she had become impure; or a spirit of jealousy came over him, and he became jealous of his wife, and she had not become impure…
From the literal Hebrew text, it seems like the wife is expected to be guilty, and the possibility that the husband’s suspicion is misplaced is almost tossed aside as an afterthought.
But even if every husband who subjects his wife to the sotah ritual has ironclad evidence of her guilt, why would the wife, who knows what she is guilty of, say “Amen, amen” to the priest’s curse? From the plain text, we see that the ritual requires her cooperation, and from the halakha (MT Hilkhot Sotah 2:1), we know that a woman can accept divorce without ketubah to avoid going through the ritual.
The answer comes from the last verse in this section of the Torah (Numbers 5:31): “The man will become clean of sin, and that woman will bear her sin.” What sin does the man become clean of? The Talmud quotes a Baraita that explains (Sotah 28a): “In a time when the man is clean from sin, the water tests his wife; if the man is not clean from sin, the water does not test his wife.” If the husband himself has had any prohibited sexual relations, whether prohibited by the Torah or by the Sages, then the adulterous wife will not die (MT Hilkhot Sotah 2:8).
If the wife survives the ritual, she has publically announced that either she is innocent of adultery and her husband has been jealous for no good reason, or that her husband has been misbehaving as well. The more the community suspects her of illicit behavior, the more they will come to suspect her husband of the same offense. For his hypocritical jealousy, the husband is punished measure for measure.
(Last year: A note regarding the nazirite)