Luke 3:3
Ver. 3. And he came into all the country about Jordan,.... He came out of the wilderness of Judea, where he first began his ministry, to some parts of the country that bordered on Jordan, and was near unto it, on either side the river; sometimes he was at Bethabara, and sometimes at Aenon, near Salim; for he did not take a tour round about all, the country that encompassed Jordan, but being at it, or in places adjacent to it, all the country round about came to him; see Mt 3:5.
Preaching the baptism of repentance for the remission of sins: this was the work and office of John, as signified by Elias, in Mal 4:5 the Jews say {n},
"the Israelites will not repent, till Elias comes; as it is said, Mal 4:5 in the land of Israel repentance delights.''
John came into this land, preaching this doctrine; See Gill on "Mr 1:4".
{n} Pirke Eliezer, c. 44.