Musnad Ahmad 944:8

Abu Abd al-Samad al-Ammi narrated to us, Mansur narrated to us, Ibrahim ibn Yazid al-Taymi narrated to us, from Amr ibn Maymun, from Abu Abd Allah al-Jadali, from Khuzaymah ibn Thabit al-Ansari, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Wipe over the leather socks for three days." And if we had asked him for more, he would have increased it for us.