Abu Dawud al-Sijistani

Sulayman ibn al-Ash'ath ibn Ishaq al-Azdi al-Sijistani was born in Sijistan (modern Afghanistan/Iran border region). He traveled extensively, studying under Imam Ahmad ibn Hanbal, Yahya ibn Ma'in, Ali ibn al-Madini, and hundreds of other scholars. He reviewed 500,000 hadiths and selected approximately 4,800 for his Sunan — the third of the six canonical hadith collections. The Sunan focuses predominantly on legal (fiqhi) hadiths and is the primary reference for deriving legal rulings. He wrote of his book: 'I collected 500,000 hadiths, then selected what is here. It is sufficient for a person's religious needs.' He died in Basra in 275 AH.