question #1 Sahih Muslim 361, Book 3, Hadith 125 : What guidance is provided for someone who doubts whether their ablution has been broken during prayer?

He should not return (from prayer) unless he hears a sound or perceives a smell (of passing wind). Abu Bakr and Zuhair b. Harb have pointed out in their narrations that it was ‘Abdullah b. Zaid.