They of the circumcision which believed (hoi ek peritomēs pistoi). The believing ones of the circumcision, more exactly.
Were amazed (exestēsan). Second aorist active indicative, intransitive, of existēmi. They stood out of themselves.
On the Gentiles also (kai epi ta ethnē). Or, even upon the Gentiles.
Was poured out (ekkechutai). Present perfect passive retained in indirect discourse of ekcheō or ekchunō, old verb, used metaphorically of the Holy Spirit also in Act 2:17 (from Joe 2:28.), Act 2:33.