Corporeal form (ṣūrah jismiyyah) is the principle by which a body is conceived as extended in length, breadth, and depth. In the philosophical model, prime matter represents receptivity, while corporeal form accounts for a body’s actually being a body.
A wooden board and an iron bar differ in material and specific characteristics, but both are spatially extended bodies. Their shared bodily extension illustrates the intended concept.
The proposition that bodies necessarily consist of matter and form is a philosophical premise, not itself a conclusion established merely by defining the terms. It remains open to theological analysis.