بل يقولون: إنه قابل لانقسامات غير متناهية
Rather, they say it admits indefinitely many divisions.
The key is capacity. The body is not being described as an already assembled infinity of physical particles, but as an extended magnitude admitting further potential subdivision.
To attack that account as though it affirmed an already existing infinite inventory of atoms would alter its premise. The distinction between a possible boundary within a continuum and a physically separated constituent is decisive.