The Self-Subsisting, The Self-Existing.
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is Al-Qayyum (in Arabic: ٱلْقَيُّومُ), His essence/nature is to exist being utterly free from dependence on anything or anyone. Al-Qayyum is the one through whom all things arise. He is Ever-Living and Self-Sustaining. Everything else in existence depends on Al-Qayyum.