Sayyiduna Kahmas Hilali (may Allah be pleased with him) says: When I accepted Islam, I came to the Noble Prophet (peace and blessings of Allah be upon him) and informed him about my Islam (and then left). Then I stayed there for a year. But I became thin and my body grew weak. Then I came to the Prophet (peace and blessings of Allah be upon him). He looked at the lower part of my body and then at the upper part (i.e., he looked at me carefully to recognize me). I said: Do you not recognize me? The Prophet (peace and blessings of Allah be upon him) said: "Who are you?" I said: I am Kahmas Hilali. The Prophet (peace and blessings of Allah be upon him) said: "Why do you look so weak?" He said: After meeting you, I have not broken my fast for a single day nor slept any night. The Prophet (peace and blessings of Allah be upon him) said: "Who ordered you to put yourself in torment? Observe the fasts of the month of patience and one fast in each month (from the remaining months)." I said: Allow me more (fasts), the Prophet (peace and blessings of Allah be upon him) said: "Observe the fasts of the month of patience and two days in each month." He said: Allow me more (because I have strength). The Prophet (peace and blessings of Allah be upon him) said: "Observe the fasts of the month of patience and three days in each month."

Muawiyah bin Qurrah narrates from his father that the Noble Prophet (peace and blessings be upon him) said: "Fasting three days every month is like fasting for a lifetime, and also breaking the fast."