Deuteronomy 21:16

Overview - Deuteronomy 21
The expiation of an uncertain murder.
10 The usage of a captive taken to wife.
15 The first-born is not to be disinherited upon private affection.
18 A rebellious son is to be stoned to death.
22 The malefactor must not hang all night on a tree.
Treasury of Scripture Knowledge

Deuteronomy 21:16  (King James Version)
Then it shall be, when he maketh his sons to inherit that which he hath, that he may not make the son of the beloved firstborn before the son of the hated, which is indeed the firstborn:

1 Chronicles 5:2 ; 26:10 2 Chronicles 11:19-22 ; 21:3 Romans 8:29 ; Philippians 4:8 ; Hebrews 12:16 Hebrews 12:17