John Gill Commentary Matthew 17:25

"He saith, Yea. And when he came into the house, Jesus spake first to him, saying, What thinkest thou, Simon? the kings of the earth, from whom do they receive toll or tribute? from their sons, or from strangers?" — Matthew 17:25 (ASV)

He saith, yes Without any hesitation, knowing it had been his master's practice; and therefore as he had done it, did not doubt but he would again:

and when he was come into the house ; that is, Peter, as both the Syriac and Persic versions express; when he was come into his own house, or at least into that where Christ was, in order to talk with him about this affair, the collectors had been speaking of to him, who seems to have been alone when they met with him; however, Christ was not with him:

Jesus prevented him ; saying what he intended to say, on that head; for he being the omniscient God, though not present, knew what question had been put to Peter, and what answer he had returned; and therefore, before Peter could lay the case before him, he puts this question to him;

saying, what think you, Simon? How does it appear to you, to your reason and understanding? in what light do you consider this matter? what is your judgment of it?

of whom do the kings of the earth take custom or tribute? of their own children, or of strangers , or others? What is the usual practice of earthly kings, whether of Judea, or of other countries? do their own children, sons, and heirs, such as are of their own family, pay? or is it only their subjects that are not of their family?