Udaysah bint Uhban (may Allah have mercy on her) said: When Sayyiduna Ali (may Allah be pleased with him) came to Basrah, he came to our house and asked: Is Abu Muslim here? We said: Yes. He came out to him, and Sayyiduna Ali (may Allah be pleased with him) said to him: Will you not help us in this matter? He said: Certainly. O slave girl, bring me that sword. She brought his sword, and he drew it from its sheath, and it was a sword of wood! Abu Muslim said to him: Your cousin, meaning the Prophet (peace and blessings be upon him), charged me that if there is tribulation among the Muslims, I should take up a sword of wood. At this Sayyiduna Ali (may Allah be pleased with him) turned back angrily and said: We have no need of you, nor of your sword.
Yazid bin Zuray' said: Yunus bin Ubayd narrated this hadith to me from this shaykh before I met him myself.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 862