Numbers 18:13

18:13 [And] whatsoever is first ripe in the land, which they shall bring unto the LORD, shall be thine; every one that is clean in thine house shall eat [of] it.

Numbers 18:15

18:15 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.

Numbers 18:17

18:17 But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they [are] holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat [for] an offering made by fire, for a sweet savour unto the LORD.