Ahmad ibn Salamah transmitted it to us, from Khalil.
Abu Dawud heard hadith from Ayman ibn Nabil—who belonged to the generation of the Tabi‘in—Ma‘ruf ibn Kharrabudh, Talhah ibn ‘Amr, Hisham ibn Abi ‘Abd Allah, Shu‘bah ibn al-Hajjaj, Sufyan al-Thawri, Bistam ibn Muslim, Abu Khaldah Khalid ibn Dinar, Qurrah ibn Khalid, Salih ibn Abi al-Akhdar, Abu ‘Amir al-Khazzaz, the two Hammads, Dawud ibn Abi al-Furat, Zam‘ah ibn Salih, Jarir ibn Hazim, Fulayh ibn Sulayman, al-Mas‘udi, Harb ibn Shaddad, Ibn Abi Dhi’b, ‘Abd al-Rahman ibn Thabit ibn Thawban, Zaydah, Isra’il, Hammam ibn Yahya, Muhammad ibn Abi Humayd, and many others besides.
His chain of transmission reaches as far down as Ibn al-Mubarak and Ibn ‘Uyaynah, and it is reported that he even met Ibn ‘Awn—something quite plausible.
Among those who narrated from him are Jarir ibn ‘Abd al-Hamid—who had himself been one of his teachers—Ahmad ibn Hanbal, ‘Amr ibn ‘Ali al-Fallas, Muhammad ibn Bashshar, Ya‘qub al-Dawraqi, Muhammad ibn Sa‘d the scribe, ‘Abbas al-Duri, Ahmad ibn Ibrahim al-Dawraqi, Ahmad ibn al-Furat, al-Kudaymi, Harun ibn Sulayman, and many others. The last of them to die was Muhammad ibn Asad al-Madani, the shaykh of Abu al-Shaykh; he possesses from Abu Dawud only a single session.
Muhammad ibn Asad lived on until the year 293 AH, and al-Tabarani met him. Thus he survived Abu Dawud by ninety years—a most uncommon occurrence. Only al-Baghawi, Abu ‘Ali al-Haddad, Ibn Kulayb, and roughly a dozen other shaykhs enjoyed a similar span, the last of that group being Abu al-‘Abbas al-Hajjar.
Al-Fallas remarked, “I have never seen anyone with a better memory than Abu Dawud.”