Matthew 22:17

“Tell us therefore, What do you think? Is it right to give tribute to Caesar, or not?”

Then they introduced the crunch question. ‘Was it right (or ‘lawful') to give tribute to Caesar or not?' The word exestin can refer either to being ‘right in itself', or alternatively to being ‘in accordance with the Law'. But the former was probably the main meaning in this context, as is indicated by the addition of ‘or not?' They wanted a practical ‘yes' or ‘no' answer that would result in His committing Himself to forbidding the payment of tribute, not just a legal decision which could be dismissed as being merely intended to be a theoretical interpretation of the Law.