Musannaf Ibn Abi Shayba 1:1873

Fadl ibn Dukayn and Yahya ibn Adam narrated to us, from Hasan ibn Salih, from ‘Asim, from Salim, from Ibn ‘Umar, from ‘Umar, who said: I saw the Messenger of Allah (may Allah bless him and grant him peace) wiping over the leather socks with water while on a journey.