Musnad Abu Ya'la al-Mawsili 108:10

Shayban narrated to us, Abu 'Awanah narrated to us, from Abu Bishr, from Sulayman ibn Qays, from Jabir ibn 'Abd Allah, who said: The Messenger of Allah (may Allah bless him and grant him peace) called Abu Taybah, and he cupped him. He asked him about his tax (payment for the service), and he said: "Three sa's." He said: So he remitted one sa' from him.