Musnad Ahmad 32:1827

'Abdullah ibn Bakr narrated to us, Humaid narrated to us, from Anas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) traveled to Khaybar, and we reached it at night. When we reached the morning, he mounted and the Muslims mounted, and I mounted behind Abu Talhah, and my foot was touching the foot of the Messenger of Allah (peace and blessings of Allah be upon him). The people of Khaybar came out with their baskets and their shovels to their crops and their lands. When they saw the Prophet (peace and blessings of Allah be upon him) and the Muslims, they turned back fleeing and said: "Muhammad and the army!" The Messenger of Allah (peace and blessings of Allah be upon him) said: "Allah is the Greatest! Khaybar is ruined. Indeed, when we descend into the courtyard of a people, then evil is the morning of those who were warned."