In Matthew 17, where did Jesus tell Peter he would find a coin to pay their tax?

Answer: In a fish's mouth

Jesus told Peter to cast a hook and open the first fish's mouth, where he would find a coin for the tax.

““But so that we may not offend them, go to the sea, cast a hook, and take the first fish you catch. When you open its mouth, you will find a four-drachma coin. Take it and give it to them for My tax and yours.””— Matthew 17:27 (BSB)