The daughter of Uhban said: Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) came to Uhban and said: What prevents you from following me? He said: My close friend, meaning the Messenger of Allah (peace and blessings be upon him), advised me; he (peace and blessings be upon him) said: "Soon there will be tribulation and division. When that happens, break your sword and take up a sword of wood." And when his condition became grave, he instructed his family to shroud him and not to dress him in a shirt. But we dressed him in a shirt, and in the morning the shirt was on the clothes peg.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 860