you shall set apart to the LORD all that first opens the womb. All the firstborn of your animals that are males shall be the LORD’s.
Here we have, I. Further directions concerning the dedicating of their firstborn to God. 1. The firstlings of their cattle were to be dedicated to God, as part of their possessions. Those of clean beasts - calves, lambs, and kids - if males, were to be sacrificed, Exo 22:30; Num 18:17, Num 18:18.
Commenting on Exodus 13:11-16
That thou shalt set apart unto the Lord all that openeth the matrix,.... Or "the womb", as in Exo 13:2, and this phrase, "set apart", explains the word "sanctify" there, and shows that it signifies the separating of such to the use and service of God, causing it to "pass", as the word (d) here used signifies, from a man's own power and use, to...
FIRSTLINGS OF BEASTS. (Exo 13:11-16) every firstling, &c.--the injunction respecting the consecration of the first-born, as here repeated, with some additional circumstances. The firstlings of clean beasts, such as lambs, kids, and calves, if males, were to be devoted to God and employed in sacrifice. Those unclean beasts, as the ass's colt, being unfit for sacrifice, were to be redeemed (Num 18:15).