الإدغام والرفع والنصب
Assimilation and the nominative and accusative inflections.
The source distinguishes the aspects of expression studied by maʿani from general linguistic rules. Case endings belong primarily to grammar and assimilation to the appropriate linguistic discipline. Maʿani asks which grammatically permissible construction suits a particular context.
Correct case assignment is a grammatical demand; understanding the rhetorical effect of permitted word order can be a matter of maʿani. The two are related, not identical.