These adult disciples were not afraid of clouds. This phrase indicates that some kind of unusual fear came over them with the cloud. It could be translated as "they were terrified."
## A voice came out of the cloud saying ##
If it is unnatural to talk about a voice speaking, it could be translated as "God spoke to them from the cloud, saying."
This can be translated as "my Son, whom I have chosen" (UDB) or "my Son, the chosen one." The word "chosen" is adding information about God's Son. It is not saying that God has more than one son. (See: information about Adjectives on [[rc://en/ta/man/translate/figs-partsofspeech]])