Bereishit – The Torah's Account
Genesis 37:3-4
The Torah states that Yaakov loved Yosef more than all his sons because he was the 'ben zekunim' — son of his old age — and made him a special coat. This favoritism caused his brothers to hate Yosef.
וְיִשְׂרָאֵ֗ל אָהַ֤ב אֶת־יוֹסֵף֙ מִכׇּל־בָּנָ֔יו כִּֽי־בֶן־זְקֻנִ֥ים ה֖וּא ל֑וֹ וְעָ֥שָׂה ל֖וֹ כְּתֹ֥נֶת פַּסִּֽים׃ וַיִּרְא֣וּ אֶחָ֗יו כִּֽי־אֹת֞וֹ אָהַ֤ב אֲבִיהֶם֙ מִכׇּל־אֶחָ֔יו וַֽיִּשְׂנְא֖וּ אֹת֑וֹ וְלֹ֥א יָכְל֖וּ דַּבְּר֥וֹ לְשָׁלֹֽם׃
Now Israel loved Joseph best of all his sons—he was the child of his old age; and he had made him an ornamented tunic. And when his brothers saw that their father loved him more than any of his brothers, they hated him so that they could not speak a friendly word to him.
Why it matters — The primary biblical text presenting the fact of Yaakov's preferential love for Yosef and its immediate cause.