“The crowd standing by
That it was thunder.
ὁ οὖν ὄχλος ὁ ἑστὼς καὶ ἀκούσας ἔλεγεν βροντὴν γεγονέναι· ἄλλοι ἔλεγον Ἄγγελος αὐτῷ λελάληκεν.
Then John uniquely indicated that that the crowd (ὁ οὖν ὄχλος) standing around (ὁ ἑστὼς) Jesus heard (καὶ ἀκούσας) this voice from heaven. However, they said (ἔλεγεν) that it was thunder (βροντὴν γεγονέναι). Others (ἄλλοι) said (ἔλεγον) that an angel (Ἄγγελος) had spoken (λελάληκεν) to Jesus (αὐτῷ). The voice of Yahweh often sounded like thunder, especially in Exodus, chapter 19, when God spoke to Moses. The accepted messengers from God were angels. Thus, any message from God could come from an angel. Something happened, but they were not sure what it was. Does thunder scare you?