15 If a man has two wives, one greatly loved and the other hated, and the two of them have had children by him; and if the first son is the child of the hated wife:

Matthew Henry's Commentary on Deuteronomy 21:15

Commentary on Deuteronomy 21:15-17

(Read Deuteronomy 21:15-17)

This law restrains men from disinheriting their eldest sons without just cause. The principle in this case as to children, is still binding to parents; they must give children their right without partiality.