And I knew him not
(Ommasin) , "by sight", as Nonnus paraphrases it; personally he had never seen him, nor had had any conversation and familiarity with him; for though they were related to each other, yet lived at such a distance, as not to know one another, or have a correspondence with each other: John was in the deserts, until the day of his showing unto Israel; and Christ dwelt with his parents at Nazareth, in a very mean and obscure manner, till he came from thence to Jordan to John, to be baptized by him; and which was the first interview they had: and this was so ordered by providence, as also this is said by John, lest it should be thought, that the testimony he bore to Jesus, and the high commendation he gave of him, arose from the relation between them; or from a confederacy and compact they had entered into:
but that he should be made manifest to Israel;
who had been for many years hid in Galilee, an obscure part of the world: and though he had been known to Joseph and Mary, and to Zacharias and Elisabeth, and to Simeon and Anna; yet he was not made manifest to the people of Israel in common; nor did they know that the Messiah was come: but that he might be known:
therefore am I come baptizing with water;
or in water, as before: for by administering this new ordinance, the people were naturally put upon inquiry after the Messiah, whether come, and where he was, since such a new rite was introduced; and besides, John, when he baptized any, he exhorted them to believe on him, which should come after him, that is, on Christ Jesus; and moreover, by Christ's coming to his baptism, he came to have a personal knowledge of him himself, and so was capable of pointing him out, and making him manifest to others, as he did.