A.T. Robertson Commentary Mark 1:9

"And it came to pass in those days, that Jesus came from Nazareth of Galilee, and was baptized of John in the Jordan." — Mark 1:9 (ASV)

In the Jordan (εις τον Ιορδανην). So in verse 10, εκ του υδατος, out of the water, after the baptism into the Jordan. Mark is as fond of "straightway" (ευθυς) as Matthew is of "then" (τοτε).

Rent asunder (σχιζομενους). Split like a garment, present passive participle. Jesus saw the heavens parting as he came up out of the water, a more vivid picture than the "opened" in Mt 3:16 and Lu 3:21. Evidently the Baptist saw all this and the Holy Spirit coming down upon Jesus as a dove because he later mentions it (John 1:32). The Cerinthian Gnostics took the dove to mean the heavenly aeon Christ that here descended upon the man Jesus and remained with him till the Cross when it left him, a sort of forecast of the modern distinction between the Jesus of history and the theological Christ.