Musnad Ahmad Hadith 23077

Yazid bin Abdullah says: I was at the camel market with Mutarrif when a Bedouin came; he had a piece of leather with him. He said, "Does anyone among you know how to read?" I said, "Yes!" and took the piece of leather from him. It was written on it: In the name of Allah, the Most Gracious, the Most Merciful. From Muhammad, the Messenger of Allah (ﷺ), to Banu Zuhair bin Aqeesh, who are a tribe of 'Ukl. If they bear witness that there is no deity except Allah and that Muhammad (ﷺ) is the Messenger of Allah, separate themselves from the polytheists, and acknowledge the share and selection of the Prophet (ﷺ) in the spoils of war (khums), then they are under the protection of Allah and His Messenger." We asked him, "What did you hear the Prophet (ﷺ) say?" He said, "I heard the Prophet (ﷺ) say: Whoever wishes that the malice in his chest be removed, he should fast the month of patience (Ramadan) and three days in every month."