Musnad Ahmad ibn Hanbal: Book 6, Hadith 21

It was narrated from Talhah bin `Ubaidullah that Two men came to the Messenger of Allah (ﷺ) and they both became Muslim, but one of them strove harder in worship than his companion. The one who strove hard in worship went out on a military campaign and was martyred. The other one remained for a year after that, then he died. Talhah said: I sat with an old man of Banu Tameem in the mosque of Basrah who had a document in his hand. That was at the time of al-Hajjaj. He said to me: “O slave of Allah, do you think that this document could help me in any way with this governor?” I said: “What is this document?” He said: “This is a document from the Messenger of Allah (ﷺ) which he wrote for us to say that no transgression should be committed against us with regard to our zakah.” I said: “No, by Allah, I do not think that this document will help you at all. But what is the story about this document?” He said: “I came to Madinah with my father when I was a young boy, with some camels of ours to sell. My father was a friend of Talhah bin `Ubaidullah at-Taimi, so we stayed with him. My father said to him: “Come out with me and sell these camels of mine for me.” Talhah said: “The Messenger of Allah (ﷺ) has forbidden townsmen to sell for Bedouins. But I will go out with you and sit with you. Offer your camels for sale and if a man comes and makes you an offer and I think he is honest and sincere, I will tell you to sell to him. So we went out to the marketplace and showed the mounts that we had for sale, and Talhah sat nearby. People made offers to us, then when a man offered what we wanted, my father said to Talhah: “Shall I sell to him?” He said: “Yes, I am sure he is honest. So sell to him.” So we sold to him. Then when we took our money and ended our business, my father said to Talhah: “Ask the Messenger of Allah (ﷺ) for a document for us, stating that no one should transgress against us with regard to our zakah.” (Talhah) said: “This is your right and it is the right of every Muslim.” He said: “Nevertheless, I would like to have a document from the Messenger of Allah(ﷺ).” So he took us out and brought us to the Messenger of Allah (ﷺ) and said: “O Messenger of Allah (ﷺ), this man is a man of the desert and is a friend of ours. He would like you to write a document for him, stating that no one should transgress against him with regard to his zakah.” The Messenger of Allah (ﷺ) said: `That is his right and it is the right of every Muslim.” He said: “O, Messenger of Allah, he would like to have something from you in writing concerning that.” So the Messenger of Allah (ﷺ) wrote this document for us.”