Ali bin Rabi'ah narrates: I heard Sayyiduna Ali (may Allah be pleased with him) when a man came to him and said: "O Commander of the Believers, why do I see you driving people along the way a man drives his camels? Is this a covenant from the Prophet (peace and blessings be upon him), or is it your own opinion?" Sayyiduna Ali (may Allah be pleased with him) said: "By Allah, I have neither been told a lie nor have I lied; I have neither gone astray nor been led astray. Rather, this is a covenant from the Messenger of Allah, and whoever fabricates a lie is disgraced."
Abu Ya'la recorded this narration. Its chain contains a narrator, al-Rabi' bin Sahl, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 14770