(טו) כִּֽי־תִהְיֶ֨יןָ לְאִ֜ישׁ שְׁתֵּ֣י נָשִׁ֗ים הָאַחַ֤ת אֲהוּבָה֙ וְהָאַחַ֣ת שְׂנוּאָ֔ה וְיָֽלְדוּ־ל֣וֹ בָנִ֔ים הָאֲהוּבָ֖ה וְהַשְּׂנוּאָ֑ה וְהָיָ֛ה הַבֵּ֥ן הַבְּכֹ֖ר לַשְּׂנִיאָֽה׃ (טז) וְהָיָ֗ה בְּיוֹם֙ הַנְחִיל֣וֹ אֶת־בָּנָ֔יו אֵ֥ת אֲשֶׁר־יִהְיֶ֖ה ל֑וֹ לֹ֣א יוּכַ֗ל לְבַכֵּר֙ אֶת־בֶּן־הָ֣אֲהוּבָ֔ה עַל־פְּנֵ֥י בֶן־הַשְּׂנוּאָ֖ה הַבְּכֹֽר׃ (יז) כִּי֩ אֶת־הַבְּכֹ֨ר בֶּן־הַשְּׂנוּאָ֜ה יַכִּ֗יר לָ֤תֶת לוֹ֙ פִּ֣י שְׁנַ֔יִם בְּכֹ֥ל אֲשֶׁר־יִמָּצֵ֖א ל֑וֹ כִּי־הוּא֙ רֵאשִׁ֣ית אֹנ֔וֹ ל֖וֹ מִשְׁפַּ֥ט הַבְּכֹרָֽה׃ {ס}
(15) If a householder has two wives, one loved and the other unloved, and both the loved and the unloved have borne him sons, but the first-born is the son of the unloved one— (16) when he wills his property to his sons, he may not treat as first-born the son of the loved one in disregard of the son of the unloved one who is older. (17) Instead, he must accept the first-born, the son of the unloved one, and allot to him a double portion of all he possesses; since he is the first fruit of his vigor, the birthright is his due.
וַיַּעֲבֹ֧ד יַעֲקֹ֛ב בְּרָחֵ֖ל שֶׁ֣בַע שָׁנִ֑ים וַיִּהְי֤וּ בְעֵינָיו֙ כְּיָמִ֣ים אֲחָדִ֔ים בְּאַהֲבָת֖וֹ אֹתָֽהּ׃
So Jacob served seven years for Rachel and they seemed to him but a few days because of his love for her.
וַיַּ֤רְא יְהוָה֙ כִּֽי־שְׂנוּאָ֣ה לֵאָ֔ה וַיִּפְתַּ֖ח אֶת־רַחְמָ֑הּ וְרָחֵ֖ל עֲקָרָֽה׃
Seeing that Leah was unloved, יהוה opened her womb; but Rachel was barren.
רְאוּבֵן֙ בְּכֹ֣רִי אַ֔תָּה כֹּחִ֖י וְרֵאשִׁ֣ית אוֹנִ֑י יֶ֥תֶר שְׂאֵ֖ת וְיֶ֥תֶר עָֽז׃
Reuben, you are my first-born,
My might and first fruit of my vigor,
Exceeding in rank
And exceeding in honor.
My might and first fruit of my vigor,
Exceeding in rank
And exceeding in honor.