Musnad Ahmad

Ibn Hujairah asked Qasim bin Burhiyah, may Allah have mercy on him, "What did you hear from Sayyiduna Ibn Amr, may Allah be pleased with him?" He said, "I heard him say that once two parties came to Sayyiduna Amr bin Al-Aas, may Allah be pleased with him, with a dispute. He judged between them, but the one against whom the decision was made became upset and went to the Noble Prophet, peace and blessings be upon him, and mentioned the whole incident. The Noble Prophet, peace and blessings be upon him, said: 'When a judge makes a decision with great care and correctness, he will receive tenfold reward, and if he makes a mistake despite being careful, he will receive double reward.'"