Inshāʾ al-dawāʾir

"In terms of being, everything has four degrees, apart from God the Exalted, although in terms of the existence which is attributed to us it only has three. The first level is the existence of a thing in its essential reality (ʿayn) - this is the second degree with respect to the Real's knowledge of originated things. The second level is its existence in knowledge - this is the first degree in regard to God the Exalted's knowledge of us, The third level is its existence in speech, and the fourth level is its existence in writing. The Being of God the Exalted in relation to our knowledge is according to these degrees, and there is no further level than this...

Know that things are according to three modes -  there is no fourth - and that knowledge cannot appertain to anything else. Whatever lies beyond these is pure non-existence, neither known nor unknown, nor related to anything... These three modes comprise: 

1. that which is qualified by Being in its own Self: it is existent by itself in its essence and its being cannot come from non-existence. It is the absolute being, not derived from anything, which no thing can pre-exist. It is that which gives all things existence, creating them, determining them, distinguishing them and ruling over them. It is the unlimited Being which cannot be relativised...

2. that is existent through God the Exalted: it is the limited being, which is described as the world, the Throne, the Pedestal (etc)...

3. that whch is qualified by neither being nor non-existence, neither temporality nor primordiality. It is ever conjoined to the eternal Real... It is the origin of the world, the origin of the One Substance, the sphere of Life, the Real by which there is creature and whatever is of the world. From this third thing the world manifests. It is the universal and intelligible Reality of realities of the world."