'First born' in the Bible

and when again He may bring in the first-born to the world, He saith, 'And let them bow before him -- all messengers of God;'

by faith he kept the passover, and the sprinkling of the blood, that He who is destroying the first-born might not touch them.

to the company and assembly of the first-born in heaven enrolled, and to God the judge of all, and to spirits of righteous men made perfect,