Musnad Ahmad 33:709

Yunus narrated to us, Hammad—meaning Ibn Zayd—narrated to us, from Ayyub, Abu al-Zubayr narrated to us, from Jabir, that the Messenger of Allah (peace and blessings of Allah be upon him), when he departed from Arafat, began to say with his hand: "Tranquility, servants of Allah; tranquility, servants of Allah."