John 8:28

εἶπεν οὖν ὁ Ἰ. Jesus therefore said; because of their gross dulness.

ὑψώσητε. On the Cross: see on John 3:14 and John 12:32. The Crucifixion was the act of the Jews, as S. Peter tells them (Acts 3:13-15).

τότε γνώσεσθε. Then shall ye perceive, as in John 8:27; the same verb is purposely used in both places (comp. John 8:43). Had they known the Messiah they would have known His Father also (John 14:9). But when by crucifying Him they have brought about His glory, then and not till then will their eyes be opened. Then will facts force upon them what no words could teach them. Comp. John 12:32.

ὅτι ἐγώ εἰμι. That I am (see on John 8:24), and (that) of Myself I do nothing (John 5:19), but (that) even as the Father taught Me, I speak these things. The construction depends on γνώσεσθε probably as far as λαλῶ, and possibly as far as ἐστιν: but it would be quite in S. John’s style to begin an independent sentence with each καί. These aorists, ἤκονσα (John 8:26; John 8:40; John 3:32; John 15:15) and ἐδίδαξεν, refer back to the point before the Incarnation when the Son was commissioned and furnished for His work. Ταῦτα λαλῶ is not put for οὕτω λαλῶ (John 12:50). There is a reminiscence of this verse in the Ignatian Epistles (Magn. VII); ὁ κύριος ἄνευ τοῦ πατρὸς οὐδὲν ἐποίησεν. See on John 8:29; John 10:9.