16 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.
Deuteronomy 21:16 Cross References - MSB
1 Chronicles 5:2
2 And though Judah prevailed over his brothers and a ruler came from him, the birthright belonged to Joseph.
1 Chronicles 26:10
10 Hosah the Merarite also had sons: Shimri the first (although he was not the firstborn, his father had appointed him as the first),
2 Chronicles 11:19-22
19 She bore sons to him: Jeush, Shemariah, and Zaham.
20 After her, he married Maacah daughter of Absalom, and she bore to him Abijah, Attai, Ziza, and Shelomith.
21 Rehoboam loved Maacah daughter of Absalom more than all his wives and concubines. In all, he had eighteen wives and sixty concubines, and he was the father of twenty-eight sons and sixty daughters.
22 Rehoboam appointed Abijah son of Maacah as chief prince among his brothers, intending to make him king.
2 Chronicles 21:3
3 Their father had given them many gifts of silver and gold and precious things, as well as the fortified cities in Judah; but he gave the kingdom to Jehoram because he was the firstborn.
Romans 8:29
29 For those God foreknew, He also predestined to be conformed to the image of His Son, so that He would be the firstborn among many brothers.
Philippians 4:8
8 Finally, brothers, whatever is true, whatever is honorable, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy—think on these things.