Musannaf Ibn Abi Shaybah

Hazrat Dawood bin Husain says that Hazrat Abu Sufyan was a mukatab (contracted) slave and used to lead the prayers for Banu Abd al-Ashhal. Among them were some companions, such as Muhammad bin Maslamah and Salamah bin Salamah. Once, the people wanted to remove him from the position of imam, so these two gentlemen listened to his recitation and said, "Can someone like him be removed from the position of imam?"