The supreme Spirit, the source of all things, has two aspects: audible and visible. In its audible aspect the Spirit is the Word, as the Bible says, or sound, as the Hindus say calling it Nada. In its physical aspect the supreme Spirit is the light, in its finer aspect the light of intelligence, and in its dense aspect the radiance of all objects. The manifestation is the phenomenon of light playing in three directions. This is really the meaning of Trinity. One direction is the light that sees, the other is the light that is seen, and the third is the light that shows all things. More plainly speaking: the eyes which see and the object that is seen and the light that enables the eyes to see the object-all three are different plays of one and the same light. In the Hadith it is said, "I have made your light and by your light I create the universe." In other words, the all-pervading Spirit says to the centralized aspect of Himself, "I made you first, and of you I have made the whole universe." In this is the key to the whole creation.