וַתַּגֵּ֥שׁ אֵלָ֖יו לֶֽאֱכֹ֑ל וַיַּֽחֲזֶק־בָּהּ֙ וַיֹּ֣אמֶר לָ֔הּ בּ֛וֹאִי שִׁכְבִ֥י עִמִּ֖י אֲחוֹתִֽי׃
And when she had brought them near unto him to eat, he took hold of her, and said unto her: ‘Come lie with me, my sister.’
Read midrashic interpretation of II Samuel 13:11: and classical rabbinic exegesis.