Musannaf Ibn Abi Shaybah

Qudamah bin Utbah narrates that I saw that Hazrat Ali (may Allah be pleased with him) was delivering a sermon when a man came to him and said, "O Commander of the Faithful! Go to the aid of Bakr bin Wa'il, for Banu Tamim have almost killed them at the place of Kunasa." Hazrat Ali (may Allah be pleased with him) sighed and then turned back to his sermon. Then another person came and said the same thing; you also sighed. Then he came a third or fourth time and repeated the same thing, so you said, "O Shaddad! Now you have dealt truthfully with me. Go to Bakr bin Wa'il and Banu Tamim and cast lots between them."