It is narrated from Hazrat Aisha (may Allah be pleased with her) that once she did not find the Prophet (peace and blessings be upon him) on her bed. She began to search with her hands and her hands touched the feet of the Prophet (peace and blessings be upon him). At that time, the Prophet (peace and blessings be upon him) was in prostration and was supplicating: "O Lord! Grant my soul piety and purify it, for You are the best to purify it. You are its Guardian and Protector."