Every thing that openeth the matrix... — (See Leviticus 27:6; Leviticus 27:26-27.) Five shekels was the redemption-price paid for each of the firstborn who were not redeemed by the Levites (Numbers 3:47).
Related Commentaries of Numbers 18:15
Numbers 18:15
15 Every thing that openeth the matrix in all flesh, which they bring unto the LORD, whether it be of men or beasts, shall be thine: nevertheless the firstborn of man shalt thou surely redeem, and the firstling of unclean beasts shalt thou redeem.