This is Sh.Musa al-'Azimi @Musa_al3azmi, author of these books on Sirah & bio of the 4 Caliphes.

These books are based on his reading of books of ahadith & their explanations (250+ volumes). But what's amazing is that he read all of them in the times between the Adhan & Iqamah! @Musa_al3azmi He is the mu'adhin of his masjid. So for every salah he'd come to the masjid, call out the Adhan, pray 2 units of salah & then sit down to read.

Whenever he comes across anything related to the Sirah of the Prophet ﷺ or the biographies of the Sahabah, he'd make a note of it.