Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Yazid bin Abdullah bin Shukhair that we were sitting in this enclosure in Basra. Then a Bedouin came, and he had a piece of leather or hide with him. That man said, "This is the letter which the Noble Prophet (peace and blessings of Allah be upon him) wrote for me." The narrator says, "I took that letter and read it out to the people. It was written in it: In the name of Allah, the Most Gracious, the Most Merciful. From Allah’s Messenger (peace and blessings of Allah be upon him), Muhammad, to the Banu Zuhair bin Aqeesh. Verily, if you establish prayer and pay zakat, and give the fifth (khums) from the spoils of war, the share of the Prophet (peace and blessings of Allah be upon him), and the selected portion for the ruler, then you will have the protection of Allah and His Messenger (peace and blessings of Allah be upon him)." The narrator asked, "Have you heard anything from the Messenger of Allah (peace and blessings of Allah be upon him)?" The Bedouin said, "I heard him say: Fasting in the month of patience and fasting three days in every month removes the whispers (evil thoughts) of the chest."