That it had thundered (brontēn gegonenai). Perfect active infinitive of ginomai in indirect discourse after elegen and the accusative of general reference (brontēn, thunder, as in Mar 3:17), “that thunder came to pass.” So the crowd “standing by” (hestōs, second perfect active participle of histēmi), but Jesus understood his Father’s voice.
An angel hath spoken to him (Aggelos autōi lelalēken). Perfect active indicative of laleō. So, when Jesus spoke to Saul on the way to Damascus, those with Saul heard the voice, but did not understand (Act 9:7; Act 22:9).