Silsilat al-Ahadith al-Sahihah

Yazid bin Abdullah bin Khair says: We were sitting in Marbad when a disheveled-haired Bedouin came to us. He had a piece of a pouch made of skin or leather. We said: This man seems to be a townsman. He said: Yes, this is a letter, the Messenger of Allah (ﷺ) wrote it for me. The people said: Give it to us. I took it and read it. It was written in it: In the name of Allah, the Most Gracious, the Most Merciful... This letter is from the Messenger of Allah (ﷺ) to Banu Zuhair bin Aqeesh. Banu Zuhair was a tribe of 'Ukl. If you bear witness that Allah alone is worthy of worship, establish prayer, pay zakat, separate yourselves from the polytheists, and give the fifth part of the spoils, the share of the Prophet (ﷺ), his chosen share, then you will be in the protection of Allah and the protection of the Messenger of Allah (ﷺ).