Exegesis:

ta Kaisaros ‘the things that are Caesar’s’; ‘what belongs to the emperor.’

apodote (only here in Mark) ‘give back,’ ‘return,’ ‘pay,’ ‘render.’

exethaumazon ep’ autō ‘they marvelled greatly at him.’

ekthaumazō (only here in N.T.: cf. thaumazō 5.20) ‘to wonder greatly,’ ‘to marvel much.’

epi ‘at’: for this use the preposition cf. 1.22.

Translation:

Render to is equivalent in many languages to ‘pay to’ or ‘give back to,’ in the sense that the coin had been minted by Caesar’s government. Accordingly, one can translate this passage as ‘pay back to Caesar the things that belong to Caesar and pay back to God the things that belong to God.’

For amazed see 1.22, 27. However, at him may require adaptation in the form of a causal statement, e.g. ‘because of him’ or ‘because of what he said,’ in instances in which one cannot say ‘amazed at a person,’ but only ‘amazed at what a person does’ or ‘because of a person.’

Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on the Gospel of Mark. (UBS Handbook Series). New York: UBS, 1961. For this and other handbooks for translators see here .