Pseudo-Chrysostom
Catena Aurea · Matthäusevangelium 3
Then cometh Jesus from Galilee to Jordan unto John, to be baptized of him. But John forbad Him, saying, I have need to be baptized of Thee, and comest Thou to me? And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered Him.
He comes to baptism, that He who has taken upon Him human nature, may be found to have fulfilled the whole mystery of that nature; not that He is Himself a sinner, but He has taken on Him a nature that is sinful. And therefore though He needed not baptism Himself, yet the carnal nature in others needed it.