"...Since Moses was alone, by having been stripped as it were of the people’s fear, he boldly approached the very darkness itself and entered the invisible things where he was no longer seen by those watching. After he entered the inner sanctuary of the divine mystical doctrine, there, while not being seen, he was in company with the Invisible. He teaches, I think, by the things he did that the one who is going to associate intimately with God must go beyond all that is visible and—lifting up his own mind, as to a mountaintop, to the invisible and incomprehensible—believe that the divine is there where the understanding does not reach...Moses’ vision of God began with light; afterwards God spoke to him in a cloud. But when Moses rose higher and became more perfect, he saw God in the darkness...The contemplation of God is not effected by sight and hearing, nor is it comprehended by any of the customary perceptions of the mind. For no eye has seen, and no ear has heard, nor does it belong to those things which usually enter into the heart of man...When, therefore, Moses grew in knowledge, he declared that he had seen God in the darkness, that is, that he had then come to know that what is divine is beyond all knowledge and comprehension..."
—Saint Gregory of Nyssa, Life of Moses, §46