Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Sha'bi that when Hazrat Ali (may Allah be pleased with him) went out for Fajr, Abdur Rahman bin Muljam and Shabib Ashja'i surrounded him. Shabib struck at him but missed, and his sword struck the wall. Then he was cornered towards the doors of Kunda, and people began to say, "Catch the one with the sword." When Shabib sensed he was about to be caught, he threw away his sword and mingled with the common people. As for Abdur Rahman, he struck Hazrat Ali (may Allah be pleased with him) on his blessed head with a sword. He too was cornered towards Bab al-Feel, and he was caught by Ariz or Awaiz Hadrami. He was then brought before Hazrat Ali (may Allah be pleased with him). Hazrat Ali (may Allah be pleased with him) said, "If I die, then if you wish, you may kill him, or you may let him go. And if I survive, then there will be retribution (qisas)."