As-Sayyid ar-Radi says: Amir al-mu'minin's words "faata'u dhikrahu" constitute the highest forms of brevity and eloquence. He means to say that he was being given news about the Prophet from the commencement of his setting out till he reached this place, and he has expressed this sense in this wonderful expression.
(1) Ibn al-'Athir, al-Nihayah, V, (w.t.'a).