Matthew
Matthew 3:5BSB·traditional attribution

People went out to him from Jerusalem and all Judea and the whole region around the Jordan.

Matthew Henry Presbyterian @wholebiblehenry

We have here an account of the preaching and baptism of John, which were the dawning of the gospel-day. Observe, I. The time when he appeared. In those days (Mat 3:1), or, after those days, long after what was recorded in the foregoing chapter, which left the child Jesus in his infancy.

Commenting on Matthew 3:1-6

John Gill Reformed Baptist @doctorgill

Then went out to him Jerusalem,.... The uncommon appearance of this person, the oddness of his dress, the austerity of his life, together with the awfulness and importance of his doctrine, and the novelty of the ordinance of baptism he administered, and the Jews having had no prophet for some hundreds of years, and imagining he might be the Messiah, quickly drew large numbers of people to him.

Albert Barnes Presbyterian @notesbybarnes

Verse 5. Jerusalem. The people of Jerusalem. All Judea. Many people from Judea. It does not mean that literally all the people went, but that great multitudes went. It was general. Jerusalem was in the part of the country called Judea. Judea was situated on the west side of the Jordan. . Region about Jordan. On the east and west side of the river; near to Jordan.