Sulaiman Ibn al-Ash'as al-Sijistani. He was born at al-Basrah A.H. 202 and died A.H. 275. Of the six Sunni collections of true hadiths, his compilation of the hadiths is collected in Sunan Abi Da'ud and has a ranking just below the Sahihs. His collection contains 4,008 traditions, supposedly collated from 500,000.