Deuteronomy 27:23

23 "May any man who has sex with his mother-in-law be under the LORD's curse." Then all of the people will say, "Amen!"

Deuteronomy 27:23 Meaning and Commentary

Deuteronomy 27:23

Cursed [be] he that lieth with his mother in law
See ( Leviticus 18:7 Leviticus 18:8 ) . All these incestuous or brutal copulations may well be supposed to be done in secret: and all the people shall say Amen;
as abhorring such incest.

Deuteronomy 27:23 In-Context

21 "May anyone who has sex with animals be under the LORD's curse." Then all of the people will say, "Amen!"

22 "May any man who has sex with his sister be under the LORD's curse. It doesn't matter whether she is his full sister or his half sister." Then all of the people will say, "Amen!"

23 "May any man who has sex with his mother-in-law be under the LORD's curse." Then all of the people will say, "Amen!"

24 "May anyone who kills his neighbor secretly be under the LORD's curse." Then all of the people will say, "Amen!"

25 "May anyone who accepts money to kill someone who isn't guilty of doing anything wrong be under the LORD's curse." Then all of the people will say, "Amen!"