Moses
Deuteronomy 15:21ESV·traditional attribution

But if it has any blemish, if it is lame or blind or has any serious blemish whatever, you shall not sacrifice it to the LORD your God.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. A repetition of the law concerning the firstlings of their cattle, that, if they were males, they were to be sanctified to the Lord (Deu 15:19), in remembrance of, and in thankfulness for, the sparing of the first-born of Israel, when the first-born of the Egyptians, both of man and beast, were slain by the destroying angel (Exo 13:2, Exo 13:15); on...

Commenting on Deuteronomy 15:19-23

John Gill Reformed Baptist @doctorgill

And if there be any blemish therein,.... In the firstling, as if it be "lame or blind", or have any ill blemish: thou shall not sacrifice it unto the Lord thy God; blemishes in any beast made it unfit for sacrifices which were required; and so all peace offerings, vows, and freewill offerings, were to be free from any, Lev 22:19, such were not fit...

Keil & Delitzsch Lutheran @keilanddelitzsch

Deu 15:19-23 Application of the first-born of Cattle. - From the laws respecting the poor and slaves, to which the instructions concerning the tithes (Deu 14:22-29) had given occasion, Moses returns to appropriation of the first-born of the herd and flock to sacrificial meals, which he had already touched upon in Deu 12:6, Deu 12:17, and Deu 14:23, and concludes by an explanation upon this point.

Commenting on Deuteronomy 15:19-23