It is narrated from Abu Nofal bin Abi Aqrab that his father asked the Prophet (peace and blessings be upon him) about fasting. The Prophet (peace and blessings be upon him) said: "Fast one day in every month." I said, "May my parents be sacrificed for you, please allow me more." He said: "What is this, wanting to do more, wanting to do more? Fast two days in every month." I said, "May my parents be sacrificed for you, I find myself stronger than that." He said: "Stronger, stronger!" Then the Prophet (peace and blessings be upon him) remained silent, until I thought that he would never allow more than that. Then the Prophet (peace and blessings be upon him) said: "Alright, fast three days in every month."