Abū Dāwūd Sulaymān ibn al-Ash‘ath ibn Isḥāq al-Azdī al-Sijistānī, commonly known as Abū Dāwūd al-Sijistānī, was a scholar of prophetic hadith who compiled the third of the six "canonical" hadith collections recognized by Sunni Muslims, the Sunan Abu Dāwūd. Wikipedia