Romans 8:29

For those whom He has known beforehand He has also pre-destined to bear the likeness of His Son, that He might be the Eldest in a vast family of brothers;

Hebrews 12:23

to the great festal gathering and Church of the first-born, whose names are recorded in Heaven, and to a Judge who is God of all, and to the spirits of righteous men made perfect,

Treasury of Scripture Knowledge

Summary

All the firstling males that come of thy herd and of thy flock thou shalt sanctify unto the LORD thy God: thou shalt do no work with the firstling of thy bullock, nor shear the firstling of thy sheep.

The firstling

Bible References

The firstling

Romans 8:29
For those whom He has known beforehand He has also pre-destined to bear the likeness of His Son, that He might be the Eldest in a vast family of brothers;
Hebrews 12:23
to the great festal gathering and Church of the first-born, whose names are recorded in Heaven, and to a Judge who is God of all, and to the spirits of righteous men made perfect,