Musannaf Ibn Abi Shayba 1:1879

Hushaym narrated to us, he said: Yazid ibn Abi Ziyad informed us, he said: Zayd ibn Wahb narrated to us, he said: Umar ibn al-Khattab wrote to him regarding wiping over the leather socks: three days and their nights for the traveler, and a day and a night for the resident.