That thou shalt set apart unto the Lord all that openeth the matrix,.... Or "the womb", as in Exodus 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 be the Lord's only:

and every firstling that cometh from a beast which thou hast; or "even every firstling" (e), explaining what is meant by what opens the matrix or womb, even every firstborn of a beast; though Jarchi interprets it of an abortion, what comes before its time, that this also should be set apart to the Lord; this must be understood of the firstlings of clean creatures, fit for food and sacrifice, such as the firstlings of cows, sheep, and goats, Numbers 18:17 as distinguished from unclean ones in the following verse:

the males shall be the Lord's; which explains what sort of firstborn of man and beast were to be set apart for his use, not females, though the first that opened the womb; but males.

(d) "et transire facies", Pagninus, Montanus, Fagius, Vatablus, Drusius, Cartwright; so Ainsworth. (e) "etiam quicunque vel quicquid aperuerit", Junius & Tremellius, Piscator, Ainsworth.

That thou shalt set apart unto the LORD all that openeth the matrix, and every firstling that cometh of a beast which thou hast; the males shall be the LORD's.

set...: Heb. cause to pass over

12, 13. 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 (Nu 18:15).

13:11-16 The firstlings of beast not used in sacrifice, were to be changed for others so used, or they were to be destroyed. Our souls are forfeited to God's justice, and unless ransomed by the sacrifice of Christ, will certainly perish. These institutions would continually remind them of their duty, to love and serve the Lord. In like manner, baptism and the Lord's supper, if explained and attended to, would remind us, and give us occasion to remind one another of our profession and duty.