Matthew 17:22-27

As they were gathering in Galilee, Jesus said to them, “The Son of Man is about to be delivered into the hands of men and they will kill him, and he will be raised on the third day.” And they were greatly distressed. When they came to Capernaum, the collectors of the two-drachma tax went up to Peter and said, “Does your teacher not pay the tax?” He said, “Yes.” And when he came into the house, Jesus spoke to him first, saying, “What do you think, Simon? From whom do kings of the earth take toll or tax? From their sons or from others?” And when he said, “From others,” Jesus said to him, “Then the sons are free. However, not to give offense to them, go to the sea and cast a hook and take the first fish that comes up, and when you open its mouth you will find a shekel. Take that and give it to them for me and for yourself.”

two-drachma - A tax of half a shekel which every Jew over 20 was expected to pay for temple upkeep (originally mentioned in Exodus 30:11-16).

"This assessment of a half-shekel (two drachmas), was collected annually for the support of the Temple.  Jesus anticipated (v 25) Peter's confusion by trying to show him that members of the royal family are exempt from the tax.  Thus Jesus, the Son of God, was not personally obligated to pay for the support of God's house because, being God, it was His Temple (Mal 3:1).  Nevertheless, to avoid offense, He would pay.  The miraculously caught fish yielded a shekel, which was equal to two half-shekels, sufficient for Jesus and Peter." (Ryrie)

Jesus spoke to him first - He knew what Peter was about to say and spoke first.

"The Jews at the time of Christ were confused about the Old Testament prophecies concerning Messiah. They recognized on the one hand that Messiah was to suffer, and on the other that Messiah would rule in power and glory. These two lines of revelation seemed to be contradictory. Jewish theology sought to harmonize the confusion by teaching the coming of two Messiahs: one to suffer an die, and the other to reign in power and glory. The disciples were not above accepting this popular conception. Christ had been speaking of a glorious kingdom in which He would rule over Israel. The three on the mount had had a revelation of that kingdom and of Christ’s glory in it; thus their attention was focused on the glory of Messiah’s reign. Like the other Jews, they could not conceive of Messiah having to suffer and die. Christ was trying to show these men that the same Messiah who would one day reign must also suffer and die. Hence, as they walked along from the slopes of Hermon to the sanctuary of Capernaum, our Lord again instructed them concerning the events that were before Him. This instruction produced two results: first, they were much confused but afraid to ask Him for further explanation (Mark 9:32); and second, they were “filled with grief” (Matthew 17:23)" (Pentecost).

from others - those not of the royal line

"He was reminding Peter (v.26) of Caesarea Philippi. There Peter had said, “Thou are the Christ, the Son of the living God.” Now Christ said to him, This half shekel is the payment of the subjects of the King, and you have said that I am the Son. When you confessed that, you did not quite understand the dignity and glory of the fact, for now you say that I pay this half shekel. You must have recognized that there is no claim on Me to pay it, if you had understood your own declaration, and the revelation of the Mount. It is for you to pay this because you are the strangers, the subjects, the people under the rule of the King. I am the Son. Thus (v.27) the King brought Himself to the place of submission in order that others might not be caused to stumble. He put Himself into fellowship with Peter. Peter, you must all pay the shekel, but I will pay it with you. You must take this place of submission; I take it side by side with you. In the commonplace of life I am with you, just as I was in the glory of the Mount, where all My Kingliness was manifested; just as I will be with you in the midst of the need of the age" (Morgan).

a shekel - a silver tetradrachma, equal to a shekel, the exact amount for the tax for two people