Deuteronomy 24:4

Her former husband, which sent her away, may not take her again to be his wife, after that she is defiled; for that is abomination before the Lord: and thou shalt not cause the land to sin, which the Lord thy God giveth thee for an inheritance.

Cross-references

In Leviticus 18:24-28, the land is defiled by sexual sins—Deuteronomy 24:4 applies the same land-defilement principle to the return of a remarried woman.

In Jeremiah 3:1, the prophet cites the law that a divorced woman cannot return to her first husband, using it as a metaphor for Israel's unfaithfulness.