John Gill Commentary Deuteronomy 9:16

"And I looked, and, behold, ye had sinned against Jehovah your God; ye had made you a molten calf: ye had turned aside quickly out of the way which Jehovah had commanded you." — Deuteronomy 9:16 (ASV)

And I looked
When he was come down from the mount, and was nigh the camp:

and, behold, you had sinned against the Lord your God ;
that plainly appeared by what they had done, and at which he was amazed; and therefore a behold is prefixed to it, it being such a gross sin, having so much impiety and ingratitude, and stupidity in it:

and made you a molten calf ;
that he saw with his eyes, and them dancing about it; see (Exodus 32:19)

you had turned aside quickly out of the way which the Lord had commanded
you ;
see (Deuteronomy 9:7) .