וַיֹּ֣אמֶר יַעֲקֹ֗ב הִשָּׁ֤בְעָה לִּי֙ כַּיּ֔וֹם וַיִּשָּׁבַ֖ע ל֑וֹ וַיִּמְכֹּ֥ר אֶת־בְּכֹרָת֖וֹ לְיַעֲקֹֽב׃
Y dijo Jacob: Júrame lo en este día. Y él le juró, y vendió á Jacob su primogenitura.
Berakhot
"Reuben" — [what means "Reuben"]? R. Eleazar answered : Leah said, "See the difference between my son and the son of my father-in-law ; for the son of my father-in-law, although he voluntarily sold his birthright — as it is written, 'And he sold his birthright unto Jacob' (ibid. xxv. 33) — see what is written of him, 'And Esau hated Jacob' (ibid, xxvii. 41)