Deuteronomy 9:21

And I took your sin, the visible expression of their idolatry, the calf which ye had made, and burned it with fire, and stamped it, and ground it very small, even until it was as small as dust; and I cast the dust thereof in to the brook that descended out of the mount, Exodus 32:20. Moses now refers to other instances which proved that the Israelites were a rebellious and stiff-necked people.