Reference for Deuteronomy 27:23

אָר֕וּר שֹׁכֵ֖ב עִם־חֹֽתַנְתּ֑וֹ וְאָמַ֥ר כָּל־הָעָ֖ם אָמֵֽן׃ (ס)

Cursed be he that lieth with his mother-in-law. And all the people shall say: Amen.

BDB