Numbers 18:15

Every thing that openeth the matrix in all flesh,.... The firstborn of every creature:

which they bring unto the Lord; as they were obliged, he claiming it as his own, Exodus 13:2;

[whether it be] of men or beasts, shall be thine; every firstborn of either, being the Lord's, became the priest's by his gift:

nevertheless, the firstborn of man shalt thou surely redeem; that is, take the redemption price for it, which was five shekels, as in

Numbers 18:16; for the original proprietor was, strictly speaking, the redeemer, and paid the money, and the priest was the receiver, to whom it was paid; see Exodus 13:13;

and the firstlings of unclean beasts shall thou redeem; with lambs, as an ass, which is put for unclean beasts, is ordered to be redeemed with a lamb, or its neck to be broken, Exodus 13:13; the Africans, the shepherds among them, as Herodotus relates k, of their firstlings they cut off the ear of the beast and throw it over a house, and then turn its neck back, for they worship only the sun and moon; which seems to be an imitation of this law.

k Melpomene, sive, l. 4. c. 188.