Genesis 19:36

וַֽיְהִי מִֽמָּחֳרָת וַתֹּאמֶר הַבְּכִירָה אֶל־הַצְּעִירָה הֵן־שָׁכַבְתִּי אֶמֶשׁ אֶת־אָבִי נַשְׁקֶנּוּ יַיִן גַּם־הַלַּיְלָה וּבֹאִי שִׁכְבִי עִמּוֹ וּנְחַיֶּה מֵאָבִינוּ זָֽרַע

And it came to pass on the morrow, that the first-born said unto the younger: ‘Behold, I lay yesternight with my father. Let us make him drink wine this night also; and go thou in, and lie with him, that we may preserve seed of our father.’

וַתַּשְׁקֶיןָ גַּם בַּלַּיְלָה הַהוּא אֶת־אֲבִיהֶן יָיִן וַתָּקָם הַצְּעִירָה וַתִּשְׁכַּב עִמּוֹ וְלֹֽא־יָדַע בְּשִׁכְבָהּ וּבְקֻמָֽהּ

And they made their father drink wine that night also. And the younger arose, and lay with him; and he knew not when she lay down, nor when she arose.

וַתֵּלֶד הַבְּכִירָה בֵּן וַתִּקְרָא שְׁמוֹ מוֹאָב הוּא אֲבִֽי־מוֹאָב עַד־הַיּֽוֹם

And the first-born bore a son, and called his name Moab—the same is the father of the Moabites unto this day.

וְהַצְּעִירָה גַם־הִוא יָלְדָה בֵּן וַתִּקְרָא שְׁמוֹ בֶּן־עַמִּי הוּא אֲבִי בְנֵֽי־עַמּוֹן עַד־הַיּֽוֹם

And the younger, she also bore a son, and called his name Ben-ammi—the same is the father of the children of Ammon unto this day.