وَأَمَّا تَقْدِيمُهُ ... فَلِتَخْصِيصِهِ بِالْمُسْنَدِ إِلَيْهِ
Fronting the predicate may restrict that predicate to the subject.
The direction of the restriction matters. A fronted locative, for example, can be presented as applicable exclusively to the named subject in a given comparison. That does not claim that the subject has no other characteristics or relations.
Restriction is a prominent effect of predicate-fronting, but it is not automatically present in every sentence. Context and grammatical structure determine whether the fronted element is truly exclusive.