And when Moses came [to Mount Sinai] at the time set by Us, and his Sustainer spoke unto him, he said: "O my Sustainer! Show [Thyself] unto me, so that I might behold Thee!" Said [God]: "Never canst thou see Me. However, behold this mountain: if it remains firm in its place, then - only then - wilt thou see Me."105
And as soon as his Sustainer revealed His glory to the mountain, He caused it to crumble to dust; and Moses fell down in a swoon. And when he came to himself, he said: "Limitless art Thou in Thy glory! Unto Thee do I turn in repentance; and I shall [always] be the first to believe in Thee!"106
Lit., "then, in time (sawfa) wilt thou see Me". As these words express the impossibility of man's seeing God - which is clearly implied in the Arabic construction - a literal rendering would not do justice to it.
Since Moses was already a believer, his words do not merely allude to belief in God's existence but, rather, belief in the impossibility of man's seeing God (Ibn Kathir, on the authority of Ibn 'Abbas).