From Azriel of Gerona, The Path of Faith and the Path of Heresy

Jewish Mysticism
If a person asks you, “What is the Creator?” you should respond to him, “He who is not deficient.” If he asks you, “Is there anything outside of Him?” you should say, “There is nothing outside of him.” If he asks you, “How did He bring forth something from nothing? Is there not a great difference between something and nothing?” you should say, “I have already told you that the one who brings forth something from nothing is not deficient, and that the something is in the nothing in the manner of the nothing, and the nothing is in the something in the manner of the something. Of this it has been said [in the book sefer yetzirah] “He made is-not is,” and they did not say, “He made something from nothing,” in order to teach you that the nothing is the something and the something is the nothing… For the something is not from the nothing alone, but rather the something and the nothing. The something and the nothing are together, and the something is none other than the nothing, and everything is one in a complete equivalence… If someone asks you if the Creator, may He be blessed, is equivalent to all, you should reply to him, “more than all, for that that which is primordial does not come before Him, for he brought something forth from nothing, and He is equivalent to all for there is nothing outside of him, not in something and not in nothing, since the Creator is the root that is equivalent to all. The path of faith and the path of heresy are equivalent at the point of the connection of is-not to is.

Translated by Hartley Lachter