Matthew 3:5 - Coke's Commentary on the Holy Bible

And all the region round about Jordan— As the river Jordan runs through a vast tract of land, it cannot be supposed that all they who lived nearest it came to John's baptism. By all the region, &c. St. Matthew therefore must mean some of those countries near Jordan, which bordered upon Judaea; as the plain of Jordan, which is by the LXX called the country about Jordan. The novelty of a prophet's appearance in Israel, the family of John, the circumstances of his birth, the extraordinarycharacter which he had maintained for strict and undissembled piety, all concurred, no doubt, with the time of his appearance, and the people's impatient desire of the Messiah's arrival, and uneasiness under the Roman yoke, to draw such vast multitudes after him. See Calmet, and Doddridge.