Neither Moses, nor Elias speak, but the Father greater than all sends a voice out of the cloud, that the disciples might believe that this voice was from God. For God has ordinarily shewn Himself in a cloud, as it is written, “Clouds and darkness are round about Him;” [Ps 97:2] and this is what is said, “Behold, a voice out of the cloud.”
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).