Jesus answered the trap with an object lesson. Instead of stating His view at once, He made the spies look at the coin and say whose it was, so that the key fact came out of their own mouths. Matthew Henry explains the point: since they used Caesar's money and enjoyed the benefit of his rule, "you ought to give tribute to him who furnished you with this convenience." The "therefore" in Jesus' answer (Luke 20:25) shows that His ruling rests on what they admitted.

"They answered and said, Caesar's" (Luke 20:24). Jesus drew the conclusion: "Render therefore unto Caesar the things which be Caesar's, and unto God the things which be God's" (Luke 20:25). The spies' plan collapsed: "they could not take hold of his words before the people: and they marvelled at his answer, and held their peace" (Luke 20:26).

The KJV "penny" is the Greek denarion, a Roman silver coin. Gill calls it "A Roman denarius," and says the image on it was "very likely Tiberius Caesar's, who was at that time emperor of Rome" (compare Luke 3:1). Barnes notes that the likeness of the reigning ruler was probably struck on the coins.

The word "image" is eikon, a likeness or portrait, and "superscription" is epigraphe, the inscription stamped on the coin. The coin itself said whose it was.

Jesus' question turned a political trap into a lesson about what belongs to whom. The coin bore Caesar's image and name, so it could be given back to Caesar. But Jesus did not stop there. He added, "and unto God the things which be God's" (Luke 20:25). Barnes, on the parallel in Matthew 22, says this may mean the yearly tribute for the temple service, or giving God what He claims: our hearts, lives, property, and influence.

The spies came to make Jesus choose between God and Caesar. He gave Caesar what bore Caesar's image and still claimed for God what is God's, and they "marvelled at his answer" (Luke 20:26).