Mus'ab bin Thabit says: There was a piece of wood near the place of the Imam. We wanted to find out the reality about it, but we could not find anyone who could tell us anything about it. Then Muhammad bin Muslim, who was in the Maqsurah, told me: One day, Sayyiduna Anas bin Malik (may Allah be pleased with him) was sitting with me and said: Do you know why this piece of wood was made? Even though I had not asked him any question about it. I said: No, by Allah! I do not know why it was made. Then Sayyiduna Anas (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) used to place his hand on it and, turning towards us, would say: Straighten and align your rows.