The Quran

143

وَلَمّا جاءَ موسىٰ لِميقاتِنا وَكَلَّمَهُ رَبُّهُ قالَ رَبِّ أَرِني أَنظُر إِلَيكَ ۚ قالَ لَن تَراني وَلٰكِنِ انظُر إِلَى الجَبَلِ فَإِنِ استَقَرَّ مَكانَهُ فَسَوفَ تَراني ۚ فَلَمّا تَجَلّىٰ رَبُّهُ لِلجَبَلِ جَعَلَهُ دَكًّا وَخَرَّ موسىٰ صَعِقًا ۚ فَلَمّا أَفاقَ قالَ سُبحانَكَ تُبتُ إِلَيكَ وَأَنا أَوَّلُ المُؤمِنينَ

Muhammad Asad

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."¹ 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!"²

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).