“Notwithstanding, lest we should offend them, go thou to the sea, and cast an hook, and take up the fish that first cometh up; and when thou hast opened his mouth, thou shalt find a piece of money: that take, and give unto them for me and thee.”
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. The provision of the tax through the miraculous fish-and-coin communicates the kingdom's generosity in meeting obligations it is not technically required to fulfill — so as not to give offense. The coin in the fish's mouth is a miracle of provision that communicates Jesus' lordship over creation (the fish, the sea, the coin) while modeling the practical wisdom of not causing unnecessary scandal through the exercise of legitimate freedoms.
Church Fathers on Matthew 17:27
The disciples were exceeding sorrowful when they heard of the Lord’s passion, and therefore that none might ascribe His suffering to compulsion, and not to a voluntary submission, he adds an incident which instances Christ’s power, and His submission; 'And when they were come to Capernaum, there came to Peter those who received the didrachma, and said unto him, Doth not your Master pay the didrachma?'
The Lord is called upon to pay the didrachma, (that is, two denarii,) for this the Law had enjoined upon all Israel for the redemption of their body and soul, and the use of those that served in the temple.
For when God slew the firstborn of Egypt, He then accepted the tribe of Levi for them. [margin note: Numb 3:44] But because the numbers of this tribe were less than the number of firstborn among the Jews, it was ordained that redemption money should be paid for the number that came short; and thence sprang the custom of paying this tax.