Musnad Abu Ya'la al-Mawsili 42:276

Zuhayr narrated to us, Habban ibn Hilal narrated to us, Hammad ibn Salamah narrated to us, from Ali ibn Zayd, from Sa'id ibn al-Musayyib, from Abu Sa'id al-Khudri, that the Prophet (may Allah bless him and grant him peace) said: "Indeed, the devil comes to one of you in his prayer and pulls a hair from his posterior, so he thinks that he has broken his ablution. So, he should not depart until he hears a sound or finds an odor."