"The Prophet was asked about doubts (concerning ablution) during prayer. He said: 'he should not leave until he hears a sound or detects an odor.'"
Sunan Ibn Majah Book 1, Hadith 248
← Previous Hadith "A complaint was made to the Prophet about a man who sensed something (some doubt about his ablution) during prayer. He said: 'No (he does not have to perform ablution) unless he notices a smell or hears a sound.'"

Sunan Ibn Majah Book 1, Hadith 247 Next Hadith → "The Messenger of Allah said: 'No ablution (is needed) unless there is an odor or a sound.'"

Sunan Ibn Majah Book 1, Hadith 249