Parallel
Deuteronomy 21:16
Brenton's English Septuagint · Berean Standard Bible
then it shall be that whensoever he shall divide by inheritance his goods to his sons, he shall not be able to give the right of the first-born to the son of the loved one, having overlooked the son of the hated, which is the first-born.
when that man assigns his inheritance to his sons he must not appoint the son of the beloved wife as the firstborn over the son of the unloved wife.