ass. Figure of speech Synecdoche (of Species), App-6, "ass" put for all animals not offered in sacrifice.
redeem. ransom. Hebrew. padah. to redeem (from bondage, by power). First occurance. Not g'aal. See note on Exodus 6:6.
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.