TRIAD supernal, both super-God and super-good, Guardian of the Theosophy of Christian men, direct us aright to the super-unknown and super-brilliant and highest summit of the mystic Oracles, where the simple and absolute and changeless mysteries of theology lie hidden within the super-luminous gloom of the silence, revealing hidden things, which in its deepest darkness shines above the most super-brilliant, and in the altogether impalpable and invisible, fills to overflowing the eyeless minds with glories of surpassing beauty …
For even the divine Moses is himself strictly bidden to be first purified, and then to be separated from those who are not so, and after entire cleansing hears the many-voiced trumpets, and sees many lights, shedding pure and streaming rays; then he is separated from the multitude, and with the chosen priests goes first to the summit of the divine ascents, although even then he does not meet with Almighty God Himself, but views not Him (for He is viewless) but the place where He is. Now this I think signifies that the most Divine and Highest of the things seen and contemplated are a sort of suggestive expression, ‘of the things subject to Him Who is above all, through which His wholly inconceivable Presence is shown, reaching to the highest spiritual summits of His most holy places; and then he (Moses) is freed from them who are both seen and seeing, and enters into the gloom of the Agnosia; a gloom veritably mystic, within which he closes all perceptions of knowledge and enters into the altogether impalpable and unseen, being wholly of Him Who is beyond all, and of none, neither himself nor other; and by inactivity of all knowledge, united in his better part to the altogether Unknown, and by knowing nothing, knowing above mind.
– Excerpt from Mystical Theology
Mystical Theology (St. Dionysius the Aeropagite)