Malik related to me that Rabia ibn Abi Abd ar-Rahman said, "An Iraqi man came before Umar ibn al-Khattab and said, 'I have come to you because of a matter which has no beginning and no end.' Umar said, 'What is it?' The man said, 'False testimony has appeared in our land.' Umar said, 'Is that so?' He said, 'Yes.' Umar said, 'By Allah! A man is not detained in Islam without just witnesses.' "