29:32כ״ט:ל״ב
1 א

(ותקרא שמו ראובן רַבּוֹתֵינוּ פֵּרְשׁוּ, אָמְרָה רְאוּ מַה בֵּין בְּנִי לְבֶן חָמִי שֶׁמָּכַר הַבְּכוֹרָה לְיַעֲקֹב, וְזֶה לֹא מְכָרָהּ לְיוֹסֵף וְלֹא עִרְעֵר עָלָיו, וְלֹא עוֹד שֶׁלֹּא עִרְעֵר עָלָיו אֶלָּא שֶׁבִּקֵּשׁ לְהוֹצִיאוֹ מִן הַבּוֹר) (ברכות ז'):

ותקרא שמו ראובן AND SHE CALLED HIS NAME REUBEN — Our Rabbis explained it thus: she said, “See (ראו) the difference between (בין) my son and my father-in-law’s son who himself sold the birthright to Jacob and yet wished to kill him afterwards. This (my son) did not sell it (his birthright) to Joseph (it must be remembered that Joseph being the founder of two tribes was regarded as the first-born of Jacob’s sons since the eldest son took a double portion in the father’s property), yet he did not raise any protest to him being regarded as the first-born and not only did he not raise a protest but he even wished to take him out of the pit and so rescue him from death (Berakhot 7b).