John 3:13

οὐδεὶς�. No one has been in heaven, so as to see and know these ἐπουράνια, excepting the Son of Man (see on John 1:51). There is probably no direct reference to the Ascension. Ἐκ τ. οὐρ. Out of heaven, at the Incarnation, when from being ἐπουράνιος He became the Son of Man.

ὁ ὢν ἐν τ. οὐρ. These words are wanting in the best MSS. and other authorities. It is much easier to account for their insertion than for their omission. It is, therefore, safest to regard them as a very early expansion of the Greek in ancient Versions. see on John 1:13. They mean, ‘Whose proper home is heaven,’ or, taking ὤν as imperf. (John 6:62; John 9:25; John 17:5), ‘Which was in heaven’ before the Incarnation, Winer, p. 429.