The source uses a description involving a body's length, width and depth to illuminate its nature.
الْجِسْمُ الطَّوِيلُ الْعَرِيضُ الْعَمِيقُ يَحْتَاجُ إِلَى فَرَاغٍ يَشْغَلُهُ
A body extended in length, breadth, and depth requires space for it to occupy.
The epithets do not introduce an unrelated classification; they unpack the idea of spatial extension and make the predicate intelligible. «الجسم يحتاج إلى فراغ» still conveys the claim, but explicitly naming the three dimensions clarifies why occupying space is at issue.