Neither the former—the Jewish, nor the last—ours.
Whence has He need for remission of sins? How is this possible for Him, Who does not have any sins?
He committed no sin—it says in the Scriptures—nor was there deceit found in His mouth (1 Pet 2:22); and further, Who of you convicteth Me of sin? (Jn 8:46).
His flesh was privy to the Holy Spirit…. If His flesh was privy to the Holy Spirit, and He was not subject to sins, then for whom was He baptised?
[…] By which baptism indeed was He baptised? Not the Jewish, nor ours, nor John’s…. He was baptised not by reason of sin and not having need of the gift of the Spirit; therefore, as we have demonstrated, this baptism was alien to the one and to the other….
He came to Jordan not for the forgiveness of sins and not for receiving the gifts of the Spirit…. For whom was He baptised, if this was done not for repentance, nor for the remission of sins, nor for receiving the gifts of the Spirit?
[…] What reason for this baptism did John declare? That Christ should become known to the people, as Paul also mentions: John therefore baptised with the baptism of repentance, so that through him they should believe on Him that cometh (Acts 19:4); this was the consequence of the baptism.
If John had gone to the home of each and, standing at the door, had spoken out for Christ and said: He is the Son of God, such a testimony would have been suspicious, and this deed would have been extremely perplexing.
So too, if he in advocating Christ had gone into the synagogues and witnessed to Him, this testimony of his might be suspiciously fabricated.
But when all the people thronged out from all the cities to Jordan and remained on the banks of the river, and when He Himself came to be baptised and received the testimony of the Father by a voice from above and by the coming-upon of the Spirit in the form of a dove, then the testimony of John about Him was made beyond all questioning.
John Chrysostom (c.347-407): Discourse on the Day of the Baptism of Christ @ Pravoslavie [slightly adapted].