וּבְנֵ֨י רְאוּבֵ֥ן בְּכֽוֹר־יִשְׂרָאֵל֮ כִּ֣י ה֣וּא הַבְּכוֹר֒ וּֽבְחַלְּלוֹ֙ יְצוּעֵ֣י אָבִ֔יו נִתְּנָה֙ בְּכֹ֣רָת֔וֹ לִבְנֵ֥י יוֹסֵ֖ף בֶּן־יִשְׂרָאֵ֑ל וְלֹ֥א לְהִתְיַחֵ֖שׂ לַבְּכֹרָֽה׃
And the sons of Reuben the first-born of Israel—for he was the first-born; but, forasmuch as he defiled his father’s couch, his birthright was given unto the sons of Joseph the son of Israel, yet not so that he was to be reckoned in the genealogy as first-born.
Berakhot
But as for my son, although Joseph forcibly deprived him of his birthright — as it is written, 'But, forasmuch as he defiled his father's couch, his birthright was given unto the sons of Joseph' (I Chron. v. 1 ) — nevertheless he was not jealous of him; for it is written, 'And Reuben heard it, and delivered him out of their hand' (Gen. xxxrii. 21)."