Musnad Ahmad 624:9

Yunus and ‘Affan narrated to us, they said: ‘Abd al-Wahid ibn Ziyad narrated to us, Abu Rawq ‘Atiyyah ibn al-Harith narrated to us, Abu al-Ghurayf narrated to us—‘Affan said: Abu al-Ghurayf is ‘Ubayd Allah ibn Khalifah—from Safwan ibn ‘Assal al-Muradi, who said: The Messenger of Allah (ﷺ) sent us on a military expedition and said: "Go forth in the name of Allah, in the way of Allah. Do not commit treachery, do not break your pledges, do not mutilate, and do not kill a newborn child." "For the traveler, there is three days and three nights for wiping over the leather socks, and for the resident, a day and a night." ‘Affan said in his narration: "The Messenger of Allah (ﷺ) sent me..."