The text raises the possibility of an occupation with no previous occupation to compare it with. Classifying every such state as either motion or rest thus needs more than the two definitions themselves.
Moreover, a philosopher who explains a body as composed of parts undergoing differently described transitions may employ a criterion of motion unlike that of the mutakallimūn. This is more than a dispute over words.
A sound argument first establishes its technical definitions, next defends the reach of its premise, and only then draws the conclusion of temporal origination. None of these steps substitutes for the others.