Maliks Muwatta Book 2, Hadith Number 47.

Yahya related to me that Malik had asked ibn Shihab how to wipe over leather socks. Ibn Shihab had put one hand under the sock and his other hand above the sock and then passed them over it.

Yahya said that Malik said, “Out of all that I have heard about the matter I like what ibn Shihab said the most.”