Sayyiduna Uwaym bin Sa'idah Ansari رضي الله عنه reports: The Messenger of Allah صلى الله عليه وسلم said to the people of Quba: "I hear from Allah that He praises you greatly regarding purity, so what is the reason for this purity?" They replied: O Messenger of Allah! We do not know anything except that our neighbors, the Jews, wash their backs after relieving themselves, so we also wash like them.