Musannaf Ibn Abi Shaybah

Hazrat Zaid bin Wahb narrates that Hazrat Abdullah entered the mosque and saw a man performing prayer with his hair tied up. When he finished the prayer, Hazrat Abdullah said, "When you pray, do not tie your hair in braids, because your hair also prostrates with you, and you receive the reward for the prostration of every hair." A man said, "I am afraid that my hair might get scattered." Hazrat Abdullah replied, "Their scattering is better than tying them."