John Wesley on Matthew 22:21

They say to him, Cesar's - Plainly acknowledging, by their having received his coin, that they were under his government. And indeed this is a standing rule. The current coin of every nation shows who is the supreme governor of it. Render therefore, ye Pharisees, to Cesar the things which ye yourselves acknowledge to be Cesar's: and, ye Herodians, while ye are zealous for Cesar, see that ye render to God the things that are God's.