Musannaf Ibn Abi Shayba 1:106

Yahya ibn Adam narrated to us, he said: Al-Hasan ibn Salih narrated to us, from Musa ibn Abi A’isha, from Yazid al-Raqashi, from Anas, that the Prophet, peace and blessings of Allah be upon him, used to interlace his beard when he performed ablution.