“And were baptized of him in Jordan, confessing their sins.”
King James Version (KJV)
3:6 Confessing their sins - Of their own accord; freely and openly. Such prodigious numbers could hardly be baptized by immerging their whole bodies under water: nor can we think they were provided with change of raiment for it, which was scarcely practicable for such vast multitudes. And yet they could not be immerged naked with modesty, nor in their wearing apparel with safety. It seems, therefore, that they stood in ranks on the edge of the river, and that John, passing along before them, cast water on their heads or faces, by which means he might baptize many thousands in a day. And this way most naturally signified Christ's baptizing them with the Holy Ghost and with fire, which John spoke of, as prefigured by his baptizing with water, and which was eminently fulfilled, when the Holy Ghost sat upon the disciples in the appearance of tongues, or flames of fire.
Mt 3:6 And were baptized of him in the Jordan. Note that the baptism took place not at, but in, in the Jordan. The Jordan, the principal stream of Palestine, rises in the mountains of Lebanon, runs south into the sea of Galilee, leaves it and descends southward along Galilee, Samaria and Judea, to the Dead Sea. In many places the streams is fordable, and furnishes good facilities for baptizing. Confessing their sins. Baptism itself, a burial in water, a "baptism into death", a symbol of the burial of one who dies to the old life, is a confession of sins. There was, perhaps, also a verbal confession. The acknowledgment of sin, repentance and baptism are prescribed as conditions of pardon.