فَفِي الِاسْتِثْنَاءِ يُؤَخَّرُ الْمَقْصُورُ عَلَيْهِ مَعَ أَدَاةِ الِاسْتِثْنَاءِ
In exception constructions, the exclusive counterpart normally follows together with the exception particle.
In “mā ḍaraba ʿAmran illā Zayd,” Zayd is singled out as agent; in “mā ḍaraba Zayd illā ʿAmran,” Amr is singled out as object.
This order presents the initial denial before identifying what is retained as the exception.