אָר֗וּר שֹׁכֵב֙ עִם־אֲחֹת֔וֹ בַּת־אָבִ֖יו א֣וֹ בַת־אִמּ֑וֹ וְאָמַ֥ר כָּל־הָעָ֖ם אָמֵֽן׃ (ס)
Cursed be he that lieth with his sister, the daughter of his father, or the daughter of his mother. And all the people shall say: Amen.
Read kabbalistic (mystical) interpretation of Deuteronomy 27:22: and classical mystical sources.