It is narrated from an Ansari companion (may Allah be pleased with him) that once some people mentioned before the Prophet Muhammad (peace and blessings be upon him) a slave woman from Banu Abdul Muttalib, saying that she spends the night in prayer and fasts during the day. The Prophet (peace and blessings be upon him) said: "But I sleep and I pray, I fast and I also leave fasting. So whoever follows my way is from me, and whoever turns away from my Sunnah is not from me. Every deed has a period of enthusiasm, which eventually comes to an end. So whoever’s enthusiasm ends in innovation has gone astray, and whoever’s enthusiasm ends in Sunnah has found guidance."