«فَخَلَجَ قَلْبِي أَنَّ أَبَا زَيْدٍ هُوَ الْمُشَارُ إِلَيْهِ»
It occurred to me that the person indicated might be Abū Zayd.
Khalaja qalbī suggests a thought stirring in the heart. The place-name Sarūj, literary skill, and familiar style point toward Abū Zayd. Yet at this moment it is a suspicion; certainty requires seeing the person clearly.