Rabi'ah said that a son of Sa'd ibn Ubadah (RA) told him that they found in his book that the Prophet (PBUH) had decided that an oath must be taken along with the presentation of a witness.
C/llaahi bin Sacad bin Abii Saraxna, warqad ayuu u qoray Cuthmaan bin Cafaan asagoo ogeysiinaya in nimankaasi ay soo aadeen dhanka Madiina si ay ugu buuqaan, wuxuuna u sheegay inay kusocdaan sifo cumra si aanan hadafkoodu loo fahmin.