Every firstling of an ass thou shalt redeem with a lamb Or kid, Exodus 12:3; and the same is to be understood of all unclean beasts in general, see Numbers 18:15. The ass seems to be particularly mentioned, because those animals were more numerous among them than other beasts of burden. If a man had not a lamb, he was to give the price of one. This lamb was to be given to the Lord; that is, to his priest.
Related Commentaries of Exodus 13:13
Exodus 13:13
13 And every firstling of an ass thou shalt redeem with a lamb;b and if thou wilt not redeem it, then thou shalt break his neck: and all the firstborn of man among thy children shalt thou redeem.