لأن الفصاحة مأخوذة في تعريف البلاغة مطلقا ولا عكس
Because fasaha is incorporated into the definition of balagha without exception, whereas the converse does not follow.
Baligh therefore includes more conditions. A baligh utterance must be fasih and fitted to its occasion; being fasih by itself does not guarantee contextual fit. The corresponding relation applies to the capacities designated by these terms for speakers.
For example, زَيْدٌ حَاضِرٌ can be a perfectly clear Arabic sentence. If the occasion calls for a decision on another matter, however, that sentence need not constitute an eloquent response to the situation.