Language:
كتاب الوضوء
4
Ablutions (Wudu')
(4)
Chapter: One should not repeat ablution if in doubt unless and until he is convinced (that he has lost his ablution by having Hadath)
(4)
باب لاَ يَتَوَضَّأُ مِنَ الشَّكِّ حَتَّى يَسْتَيْقِنَ

Narrated `Abbad bin Tamim:

My uncle asked Allah's Messenger (ﷺ) about a person who imagined to have passed wind during the prayer. Allah' Apostle replied: "He should not leave his prayers unless he hears sound or smells something."

حَدَّثَنَا عَلِيٌّ، قَالَ حَدَّثَنَا سُفْيَانُ، قَالَ حَدَّثَنَا الزُّهْرِيُّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، وَعَنْ عَبَّادِ بْنِ تَمِيمٍ، عَنْ عَمِّهِ، أَنَّهُ شَكَا إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم الرَّجُلُ الَّذِي يُخَيَّلُ إِلَيْهِ أَنَّهُ يَجِدُ الشَّىْءَ فِي الصَّلاَةِ‏.‏ فَقَالَ ‏ "‏ لاَ يَنْفَتِلْ ـ أَوْ لاَ يَنْصَرِفْ ـ حَتَّى يَسْمَعَ صَوْتًا أَوْ يَجِدَ رِيحًا ‏"‏‏.‏
Reference : Sahih al-Bukhari 137
In-book reference : Book 4, Hadith 3
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 139
  (deprecated numbering scheme)