Musannaf Ibn Abi Shayba 3:5667

Ibn Mahdi narrated to us, from Zuhayr ibn Muhammad, from Zayd ibn Aslam, from Aban ibn Uthman, who said: He saw a man praying while he had tied his hair. He said, "O son of my brother, the likeness of one who prays while his hair is tied is like the likeness of one who prays while he is bound."