Weak (da'if) — scholars do not use this report as evidence for rulings.
Muhammad b. Muslim b. al-Sa’ib said:one day I prayed by the side of Anas b. Malik. He said ; Do you know why this stick is placed here ? I said : No, by Allah. He said; The Messenger of Allah (ﷺ) used to put his hand upon it and say: Keep straight and straighten your rows