Albert Barnes Commentary Matthew 22:21

"They say unto him, Caesar`s. Then saith he unto them, Render therefore unto Caesar the things that are Caesar`s; and unto God the things that are God`s." — Matthew 22:21 (ASV)

Render therefore unto Caesar, etc. Caesar's image and name on the coin proved that it was his. It was proper, therefore, to give it back to him when he called for it. But while this was done, He took occasion to charge them also to give to God what He claimed. This may mean either:

1. The annual tribute due to the temple service, implying that paying tribute to Caesar did not free them from the obligation to do that; or
2. That they should give their hearts, lives, property, and influence, all to God, as His due.

(Regarding "unto God," see Malachi 1:6-8; Malachi 3:8–10.)