And narrated to me Muhammad ibn Abi Bakr al-Muqaddami and Zuhayr ibn Harb—both said: narrated to us Yahya, who is Ibn Sa'id, from 'Ubayd Allah. And narrated to us Abu Bakr ibn Abi Shaybah and Ibn Numayr—and the wording is theirs—Ibn Numayr said: narrated to us my father, and Abu Bakr said: narrated to us Abu Usamah—both said: narrated to us 'Ubayd Allah, from Nafi', from Ibn 'Umar, that 'Umar said: "O Messenger of Allah, may one of us sleep while he is in a state of major ritual impurity (junub)?" He said: "Yes, if he performs ablution (wudu')."