Luke 3:22

And the Holy Ghost descended in a bodily shape
In a corporeal form, in a visible manner, and was seen with bodily eyes, at least by John the administrator; to whom this was a signal of his being the Messiah, and a fresh confirmation of it:

like a dove upon him;
either in the form of a dove, or this corporeal form, whatever it was, descended and hovered on him as a dove does:

and a voice came from heaven;
at the same time the Holy Ghost came down upon him; which said,

thou art my beloved Son, in thee I am well pleased:
and was the voice of the Father; and the whole of this was an answer of Christ's prayer; (See Gill on Matthew 3:16) (See Gill on Matthew 3:17) (See Gill on Mark 1:11).