Musnad Abu Ya'la al-Mawsili 207:1

Dawud ibn Rashid narrated to us, Ismail ibn Ayyash narrated to us, from Ishaq ibn Abi Farwah, that Abu Hazim, the freed slave of Abu Ruhm al-Ghifari, informed him, from Abu Ruhm and another, that they were both horsemen on the day of Hunayn. They were given six shares: four for their two horses and two shares for themselves. They sold the two shares for two young camels.