Moses de Leon, The Book of the Pomegranate, p. 171

Jewish Mysticism
Because man is encompassed by all spiritual things, and there is within him the image of all worlds and things revealed and concealed, thus, because it is from the root of thought that is in man that all things emanate forth as a chain and they go forth in their order in a supernal fashion, when he reaches the secret of the concealed and hidden things, it is important to look into and have intention in them, in his heart and spirit, in the bond of his soul and thoughts, like a flame bound to a coal.

Translated by Hartley Lachter