Musnad Ahmad 32:1688

'Affan narrated to us, Hammam narrated to us, Qatadah narrated to us, from Anas, that the Prophet, peace and blessings of Allah be upon him, came upon a man driving a sacrificial camel. He said: "Ride it." The man said: "It is a sacrificial camel." He said: "Woe to you, ride it."