Treasury of Scripture Knowledge

Summary

Because all the firstborn are mine; for on the day that I smote all the firstborn in the land of Egypt I hallowed unto me all the firstborn in Israel, both man and beast: mine shall they be: I am the LORD.

Bible References

Because

Luke 2:23
as it is written in the Law of the Lord: "Every first-born male shall be called holy to the Lord."
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,