But lest we cause them to fall, go to the lakea and cast in a hook, and take up the first fish that comes up, and when you have opened his mouth, you will find a silver stater coin. Take that and give it to them for you and me.” Bible see other translations
This is referring to the “Sea of Galilee.”

“the lake.” The “sea” of Galilee is actually quite a small lake, only 7 miles (11.2 km) across and 12 miles (19.3 km) long, and the entire lake can be seen from the escarpments on both the east and west sides. The Greek word thalasso, lake, sea, or ocean, does not really refer to the size of the body of water, and thus has to be translated into the English “lake,” “sea,” or “ocean” by knowing the body of water that is being referred to (see commentary on Matt. 4:18).

Commentary for: Matthew 17:27