Yazid bin Abdullah bin al-Shikhkhir reports this statement from a bedouin: I heard the Prophet (peace and blessings be upon him) say: "Fasting the month of patience and three days of every month removes the rancour (or the whisperings) of the chest."
Imam Ahmad and Imam al-Tabarani in al-Mu'jam al-Kabir recorded it; however, he (al-Tabarani) reported the wording: "A man from the tribe of Ukl narrated to us." The narrators of Imam Ahmad are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5184