A.T. Robertson Commentary John 20:22

"And when he had said this, he breathed on them, and saith unto them, Receive ye the Holy Spirit:" — John 20:22 (ASV)

He breathed on them (ενεφυσησεν). First aorist active indicative of εμφυσαω, late verb, here only in N.T. though eleven times in the LXX and in the papyri. It was a symbolic art with the same word used in the LXX when God breathed the breath of life upon Adam (Genesis 2:7). It occurs also in Eze 37:9. See Christ's promise in Joh 16:23. Jesus gives the disciples a foretaste of the great pentecost.

Receive ye the Holy Ghost (λαβετε πνευμα αγιον). Second aorist (ingressive) active imperative of λαμβανω. Note absence of article here (πνευμα αγιον) though το πνευμα το αγιον in 14:26. No real distinction is to be observed, for Holy Spirit is treated as a proper name with or without the article.