Musnad Ahmad 1130:2

Abu Mu’awiyah narrated to us, ‘Asim narrated to us, from ‘Isa ibn Hattan, from Muslim ibn Salam, from ‘Ali ibn Talq, who said: A Bedouin came to the Prophet, may Allah bless him and grant him peace, and said: O Messenger of Allah, we are in the desert, and one of us may pass a little wind, and water is scarce. He said: The Messenger of Allah, may Allah bless him and grant him peace, said: "If one of you passes wind, let him perform ablution, and do not approach women in their anuses, for Allah is not ashamed of the truth." Muhammad ibn Ja’far narrated to us, Shu’bah narrated to us, from ‘Asim al-Ahwal, I heard ‘Isa ibn Hattan narrating from Muslim ibn Salam, and he mentioned the hadith.