Musnad Ahmad 6:24

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, Salim ibn Abi Umayyah Abu al-Nadr narrated to us, he said: An old man from Banu Tamim sat with me in the mosque of Basra, and with him was a scroll in his hand—he said: And this was in the time of al-Hajjaj—so he said to me: "O servant of Allah, do you see this document as being of any avail to me before this ruler?" I said: "And what is this document?" He said: "This is a document from the Messenger of Allah, may Allah bless him and grant him peace, which he wrote for us: that no transgression be committed against us regarding our alms (sadaqat)." I said: "No, by Allah, I do not think it will be of any avail to you at all. And how was the affair of this document?" He said: "I came to Medina with my father while I was a young boy, with camels of ours to sell. My father was a friend of Talhah ibn Ubayd Allah al-Taymi, so we stayed with him. My father said to him: 'Go out with me and sell these camels of mine for me.' He said: 'The Messenger of Allah, may Allah bless him and grant him peace, has forbidden that a town-dweller sell for a desert-dweller, but I will go out with you and sit, and you present your camels. If you are satisfied with a man’s trustworthiness and honesty from those who bargain with you, I will command you to sell to him.'" He said: "So we went out to the market and stood our camels, and Talhah sat nearby. Men bargained with us until, when a man gave us what we were satisfied with, my father said to him: 'Shall I sell to him?' He said: 'Yes, I am satisfied with his trustworthiness for you, so sell to him.' So we sold to him. When we had received what was ours and finished our need, my father said to Talhah: 'Get us a document from the Messenger of Allah, may Allah bless him and grant him peace, that no transgression be committed against us regarding our alms.' He said: 'This is for you and for every Muslim.' He said: 'Despite that, I would like to have a document from the Messenger of Allah, may Allah bless him and grant him peace, in my possession.'" He said: "So he went out until he brought us to the Messenger of Allah, may Allah bless him and grant him peace, and said: 'O Messenger of Allah, this man is from the people of the desert, a friend of ours, and he would like for you to write a document for him that no transgression be committed against him regarding his alms.' The Messenger of Allah, may Allah bless him and grant him peace, said: 'This is for him and for every Muslim.' He said: 'O Messenger of Allah, he would like to have a document from you regarding that.' So the Messenger of Allah, may Allah bless him and grant him peace, wrote this document for us." The end of the hadith of Talhah ibn Ubayd Allah, may Allah be pleased with him.