Moses
Deuteronomy 9:21BSB·traditional attribution

And I took that sinful thing, the calf you had made, and burned it in the fire. Then I crushed it and ground it to powder as fine as dust, and I cast it into the stream that came down from the mountain.

Matthew Henry Presbyterian @wholebiblehenry

That they might have no pretence to think that God brought them to Canaan for their righteousness, Moses here shows them what a miracle of mercy it was that they had not long ere this been destroyed in the wilderness: "Remember, and forget not, how thou provokedst the Lord thy God (Deu 9:7); so far from purchasing his favour, thou hast many a time laid...

Commenting on Deuteronomy 9:7-29

John Gill Reformed Baptist @doctorgill

And I took your sin, the calf which ye had made,.... Which was the object of their sin, which lay in making and worshipping it; see Isa 31:7. and burnt it with fire, and stamped it; with his feet after it was burnt, to bring it into small pieces: and ground it very small; or, as the Targum of Jonathan,"ground it in a mortar well;''the...

Jamieson-Fausset-Brown Reformed @jfbcommentary

I cast the dust thereof into the brook that descended out of the mount--that is, "the smitten rock" (El Leja) which was probably contiguous to, or a part of, Sinai. It is too seldom borne in mind that though the Israelites were supplied with water from this rock when they were stationed at Rephidim (Wady Feiran), there is nothing in the Scripture narrative which should...