ولا جسم؛ لأنه مركب ومتحيز
Nor a body, because a body is composite and spatially located.
In the classical technical sense, a body has dimensions, parts and spatial delimitation. Applying the term to God would imply composition and boundedness, both incompatible with the self-sufficiency and transcendence of the Necessary Being.
Denying corporeality is not equivalent to denying real existence. Non-bodily does not mean nonexistent. The claim that everything real must occupy physical dimensions would itself require proof.