John 8:28

When ye have lifted up the Son of man (otan upswshte ton uion tou anqrwpou). Indefinite temporal clause with otan (ote + an) and the first aorist active subjunctive of upsow, to lift up (Koin verb from upso, height), used several times in John of the Cross of Christ ( Genesis 3:14 ; Genesis 8:28 ; Genesis 12:32 Genesis 12:34 ). It is unnecessary to render the aorist subjunctive as if a future perfect, simply "whenever ye lift up" (actually lift up, ingressive aorist). In Acts 2:33 the verb is used of the Ascension. Shall ye know (gnwsesqe). Future (ingressive aoristic) middle of ginwskw. Cognoscetis ex re quod nunc ex verbo non creditis (Bengel). But the knowledge from the facts like the fall of Jerusalem will come too late and will not bring a change of heart. The Holy Spirit will convict them concerning judgment ( Acts 16:8 ). For I am (egw eimi) see on verse 24|. As the Father taught me (Kaqw edidasken me o pathr). This claim Jesus repeats (see verse Acts 26 ) and clearly makes on his arrival at the feast ( Acts 7:16 ). This fact marks Jesus off from the rabbis.