Musannaf Ibn Abi Shayba 13:864

Abu Bakr narrated to us, he said: Hafs narrated to us, from Muhammad bin Zayd, from Talha bin Abdullah bin Awf, who said: The Messenger of Allah (peace and blessings of Allah be upon him) ordered a crier, so he cried out until he reached the mountain pass: "The testimony of an adversary or a person of ill repute is not permissible, and the oath is upon the defendant."