Exodus 13:11

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. Those of unclean beasts, as colts, were to be redeemed with a lamb, or knocked on the head. For whatsoever is unclean (as we all are by nature), if it be not redeemed, will be destroyed, Exo 13:11, Exo 13:13. 2. The firstborn of their children were to be redeemed, and by no means sacrificed, as the Gentiles sacrificed their children to Moloch. The price of the redemption of the firstborn was fixed by the law (Num 18:16) at five sheckles. We were all obnoxious to the wrath and curse of God; by the blood of Christ we are redeemed, that we may be joined to the church of the firstborn. They were to redeem their children, as well as the firstlings of the unclean beasts, for our children are by nature polluted. Who can bring a clean thing out of an unclean? II. Further directions concerning the catechising of their children, and all those of the rising generation, from time to time, in this matter.

— Matthew Henry's Concise Commentary (public domain)