Deuteronomy 27:23 is a curse pronounced on anyone who has sexual relations with his mother-in-law. In the ceremony at Shechem, the Levites spoke these curses aloud, and the people answered “Amen” to show they agreed to the terms of the covenant. Moses gave the instruction before Israel entered the land, so the verse is part of a public warning spoken to the whole community.
‘Cursed is he who lies with his mother-in-law.’ All the people shall say, ‘Amen.’
Deuteronomy 27:23 (WEB)
What Deuteronomy 27:23 Means
The verse names one specific act and declares it cursed. The word “cursed” here means something set apart for judgment and rejected by the covenant community, not a casual insult. The phrase “lies with” refers to sexual intercourse, and the mother-in-law is the mother of one’s wife. The verse does not describe a punishment in detail. It states that such an act places a person outside the blessing of God’s covenant.
The verse also does not offer a general lesson about family tension or in-law relationships. Its concern is a clear boundary around the family, the kind of boundary that protects marriage and household life. Read alone, it is a law with a sharp edge, and the surrounding verses show that it belongs to a larger pattern of protecting the family from sexual disorder.
The Context of Deuteronomy 27:23
Deuteronomy is Moses’ final address to Israel on the plains of Moab, traditionally dated to the end of the forty years in the wilderness. The audience is the second generation, the people about to cross the Jordan and take the land. Chapter 27 records instructions for a covenant ceremony: six tribes stand on Mount Gerizim to bless and six on Mount Ebal to pronounce curses, and the Levites recite the curses in turn.
Verses 20 through 26 form a run of curses, each beginning with “Cursed is he who” and ending with the people’s “Amen.” Verse 23 sits between the curse against lying with one’s father’s wife and the curse against sexual relations with a sister. Seen in that list, the verse reads as one item in a careful set of boundaries around close family relationships, and the whole sequence closes with a broader curse on anyone who does not keep the words of the law.
Key Phrases in Deuteronomy 27:23
Leviticus 18:8
“‘You shall not uncover the nakedness of your father’s wife. It is your father’s nakedness.
(WEB)
This verse gives the fuller list of forbidden sexual relations within the family and treats the mother-in-law and father’s wife within the same protective framework. Reading it alongside Deuteronomy 27:23 shows that the curse rests on a settled, detailed law about family boundaries.
1 Corinthians 6:18
Flee sexual immorality! “Every sin that a man does is outside the body,” but he who commits sexual immorality sins against his own body.
(WEB)
Paul urges believers to flee sexual immorality, which shows that the concern behind the Old Testament law carries forward into the New Testament. The verse connects the physical act to the wider call to honor God with the body.
A Short Prayer From Deuteronomy 27:23
Lord, you know how easily our desires can pull us toward what harms our families and our own hearts. Guard our relationships with a clear and holy boundary, and give us the courage to keep it even when the temptation feels strong. Where we have already stepped across a line, bring us to honest repentance and to the help we need. Help us to honor the people you have placed around us, and to keep our households faithful to you. Amen.
