It is narrated from Hazrat Anas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) once entered the mosque and saw a rope hanging between two pillars. He asked, "What is this rope?" The people replied, "This is Zainab's rope. When she feels lazy or tired while praying, she ties herself to it." The Prophet (peace and blessings be upon him) said, "Untie it." Then he said, "When any one of you prays, he should pray as long as he remains energetic, and when he feels lazy or tired, he should stop."