Romans 8:29

For those whom God chose from the first he also destined from the first to be transformed into likeness to his Son, so that his Son might be the eldest among many Brothers.

Hebrews 12:23

to the festal gathering and assemblage of God's Eldest Sons whose names are enrolled in Heaven, to God the Judge of all men, to the spirits of the righteous who have attained perfection,

Treasury of Scripture Knowledge

Summary

Now the sons of Caleb the brother of Jerahmeel were, Mesha his firstborn, which was the father of Ziph; and the sons of Mareshah the father of Hebron.

His first-born

Bible References

His first-born

Romans 8:29
For those whom God chose from the first he also destined from the first to be transformed into likeness to his Son, so that his Son might be the eldest among many Brothers.
Hebrews 12:23
to the festal gathering and assemblage of God's Eldest Sons whose names are enrolled in Heaven, to God the Judge of all men, to the spirits of the righteous who have attained perfection,