Musnad Ahmad 5:264

'Affan narrated to us, Shu'bah narrated to us, he said: Salamah ibn Kuhayl informed me, he said: I heard Hujayyah ibn 'Adi, a man from Kindah, say: I heard a man ask 'Ali. He said: "I bought this cow for the sacrifice." He ('Ali) said: "For seven." He said: "The horn (is broken)." He said: "It does not harm you." He said: "The lameness." He said: "When it reaches the place of sacrifice, then slaughter it." Then he said: "The Messenger of Allah, peace and blessings of Allah be upon him, commanded us to examine the eye and the ear."