Musannaf Ibn Abi Shaybah

Hazrat Khallas narrates that two men came to Hazrat Ali (may Allah be pleased with him) and testified against a man that he had committed theft, so he (Ali) had his hand cut off. Then those two brought another man and said, "He is the thief." Thus, Hazrat Ali accused both of them of slander and made them responsible for the blood money of the first person.