JMNT(i)
5 Now consider this! While he was still speaking, a cloud composed of light (or: a cloud full of light; a cloud radiating light; a luminous cloud; an illuminated cloud) suddenly brought shade upon them (or: cast a shadow over them; overshadowed, or enveloped them). And think of this! A Voice – from out of the midst of the cloud – progressively saying, "This Man continues existing being My Son! The Beloved One (or: The One exemplifying and expressing My love) within Whom I think good thoughts (or: in Whom I imagine thoughts of wellness and ease; in Whom I appear well; in Whom I approve and of Whom I have a good opinion). Make it a habit to listen, to continue paying attention, and then to [really] hear Him (implies: obey Him)!"
6 At once, upon hearing [this], the disciples fell (= flung themselves) upon their faces and then were made extremely afraid (or: became terrified).