«وَتَظُنُّ سَلْمَى أَنَّنِي أَبْغِي بِهَا بَدَلًا»
Salmā imagines that I seek someone to replace her.
«أَرَاهَا فِي الضَّلَالِ تَهِيمُ»
I see her wandering in delusion.
The clause «أَرَاهَا» states the poet’s own judgment on her assumption. A misleading coordination might place that judgment under the scope of Salmā’s conjecture. Faṣl preserves the intended distinction: first her supposition, then the poet’s independent appraisal.