Deuteronomy 21:16
then when he bequeaths his possessions to his sons, he must not give preference to the firstborn of the beloved wife over the firstborn of the unloved wife.
1 Chronicles 26:10
Hosah, one of Merari's sons, had these sons: Shimri their chief (though not the firstborn, his father had appointed him chief),
1 Chronicles 5:2
Even though Judah became prominent among his relatives that is, the Commander-in-chief will be his descendant nevertheless the right of the firstborn went to Joseph.)
2 Chronicles 11:19-22
who bore him these sons: Jeush, Shemariah, and Zaham.
2 Chronicles 21:3
Their father gave them many gifts made of silver, and gold, as well as valuable things, along with fortified cities in Judah, but he passed the kingdom to Jehoram because Jehoram was his firstborn.
Romans 8:29
For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that the Son might be the firstborn among many brothers.
Philippians 4:8
Finally, brothers, whatever is true, whatever is honorable, whatever is fair, whatever is pure, whatever is acceptable, whatever is commendable, if there is anything of excellence and if there is anything praiseworthy keep thinking about these things.
Hebrews 12:16-17
No one should be immoral or godless like Esau, who sold his birthright for a single meal.