Matthew 3:5

Then went out The form of the Greek verb implies continued action — the people “kept on going out.” The crowds kept coming to see and hear John and to be baptized by him. The fact that people kept on coming testifies to the glowing reports carried back by those who had already heard him. The fact that they were willing to drop their work and go for miles out into the wilderness bears witness to the magnetic drawing power of the message he bore.

All Judaea. John’s ministry, like that of Christ, began in the vicinity of Judea, perhaps to give the Jewish leaders themselves the first opportunity to hear and accept the message (Mark 1:5; cf. DA 231, 232).

All the region. Gradually, as the word was spread by those who returned from hearing John, people came from yet greater distances (cf. Luke 3:3). It is evident, also, that John himself moved about from place to place, the better to reach people everywhere (see on v. 1).