Musannaf Ibn Abi Shayba 13:1024

Abu Bakr narrated to us, he said: Ali bin Mushir narrated to us, from Ibn Abi Layla and Nafi’, from Ibn Umar, that Abu Tayyiba cupped the Prophet, may Allah bless him and grant him peace. He asked him, "How much is your tax (kharaj)?" He said, "Three sa’s." He said, so he remitted one sa’ from his tax for him and gave him a wage.