Deuteronomy 21:17

却要认所恶之妻生的儿子为长子，将产业多加一分给他；因这儿子是他力量强壮的时候生的，长子的名分本当归他。」

què yào rèn suǒ è zhī qī shēng de ér zi wèi zhǎng zǐ ， jiāng chǎn yè duō jiā yì fēn gěi tā ； yīn zhè ér zi shì tā lì liàng qiáng zhuàng de shí hòu shēng de ， zhǎng zǐ de míng fēn běn dāng guī tā 。」

but he shall acknowledge the firstborn, the son of the hated, by giving him a double portion of all that he has; for he is the beginning of his strength. The right of the firstborn is his.