Numbers 5:12-14

to give the Israelites the following instructions. It may happen that a man becomes suspicious that his wife is unfaithful to him and has defiled herself by having intercourse with another man. But the husband may not be certain, for his wife may have kept it secret—there was no witness, and she was not caught in the act. Or it may happen that a husband becomes suspicious of his wife, even though she has not been unfaithful.