Musannaf Ibn Abi Shayba 28:761

Yahya ibn Sa'id al-Qattan narrated to us, from Habib ibn Shihab, from his father, who said: I was the first to be sent as a delegate to the gate of Tustar. He said: Al-Ash'ari was thrown from his horse. When we conquered it, he appointed me over ten of my people, and he granted me an extra share [of the spoils] in addition to my share and the share of my horse, before the [general] distribution of the spoils.