#Alahazrat was an expert in hadith. Often, when he quotes a hadith, his knowledge is so expansive that he doesn't reference it from one book but sometimes 5, 10, 20 or even more books. It seems as though all the books on the said topic lay open before him and he is simply penning their names. Moreover, he even tells us which muhaddith has that hadith from which companion. For example: 1. In al-Amnu wa'l Ula, he references a hadith from 9 sahabah from 34 books. 2. In the same book, he references a hadith from 10 sahabah from 23 books. 3. In the same book, he references a hadith from 4 sahabah from 14 books. 4. In JazaAllah al-Aduwwah, he references a hadith from 14 sahabah from 18 books. 5. In Radd al-Qaht wa'l Waba, he references a hadith from 10 sahabah and a tabiyi from 23 books. 6. In Ataya al-Qadir, he references a hadith from 10 sahabah from 43 books. 7. In one fatwa, he references a hadith from 15 sahabah from 34 books. 8. Regarding zakah being prohibited for Banu Hashim, he references 25 hadiths from 20 sahabah from 15 books. These are but a few examples of his expansive reading and depth in hadith.