Musannaf Ibn Abi Shayba 28:894

Waki’ narrated to us, he said: Sufyan narrated to us, from Abu Hayyan, from a man from the people of Medina, from the scribe of Ubayd Allah, who said: Abdullah ibn Abi Awfa wrote that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Do not wish to meet the enemy, and ask Allah for well-being. But if you meet them, and they raise a clamor and shout, then upon you is silence."