Moses’ vision of God began with light (Exod. 19.18); afterwards God spoke to him in a cloud (Exod. 20.21). But when Moses rose higher and became more perfect, he saw God in the darkness (Exod. 24.15-18).
— Gregory of Nyssa,
Commentary on the Song of Songs,
quoted in An Anthology of Christian Mysticism
edited by Harvey D. Egan.