john 3:13 And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven. - Free Bible Online

      13. no man hath ascended, &c.--There is something paradoxical in this language--"No one has gone up but He that came down, even He who is at once both up and down." Doubtless it was intended to startle and constrain His auditor to think that there must be mysterious elements in His Person. The old Socinians, to subvert the doctrine of the pre-existence of Christ, seized upon this passage as teaching that the man Jesus was secretly caught up to heaven to receive His instructions, and then "came down from heaven" to deliver them. But the sense manifestly is this: "The perfect knowledge of God is not obtained by any man's going up from earth to heaven to receive it--no man hath so ascended--but He whose proper habitation, in His essential and eternal nature, is heaven, hath, by taking human flesh, descended as the Son of man to disclose the Father, whom He knows by immediate gaze alike in the flesh as before He assumed it, being essentially and unchangeably 'in the bosom of the Father'" (Joh 1:18).

JFB.