Sayyiduna Salamah al-Hamdani (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) wrote a letter to Qays bin Malik al-Arhabi: "O Allah, seeking blessing through Your name (I begin). This is from Sayyiduna Muhammad (peace and blessings be upon him), the Messenger of Allah, to Qays bin Malik. Peace be upon you, and may the mercy of Allah Almighty, His blessings and His forgiveness descend. To proceed: I appoint you as an official over your people, over their desert-dwellers and their town-dwellers, over their freed clients and their dependents. And I grant you two hundred sa' of the grain of Yasar (this is the name of a mountain in Yemen) and two hundred sa' of the raisins of Khaywan (this is a city in Yemen) (that is, I fix this as your stipend), and this will remain for you and for your descendants after you forever and ever." Qays says: This saying of the Prophet (peace and blessings be upon him), "forever and ever," is the most beloved thing to me; now I hope that my descendants will remain forever and ever. The narrator Yahya says: "Urbuhum" means the desert-dwellers, and "Khumuruhum" means the town-dwellers, that is, the people living in the settlements.
Abu Ya'la recorded it. Its chain contains a narrator, Amr bin Yahya bin Salamah, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزكاة / 4453