Ibn Sīnā argued that in every created thing what it is, its essence, is distinct from its existence, which it receives from another; only in God, the Necessary Existent, are they identical. The distinction passed to Aquinas and the Latin West, and Mullā Ṣadrā later argued for the primacy of existence.
Essence and existence
Avicenna’s distinction between what a thing is and the fact that it is, central to medieval metaphysics.
Also: mahiyya and wujud