Allah’s Messenger (ﷺ) said: “Satan comes to one of you in Salat and blows air in his bottom, so he imagines that he has realised air yet he did not. So if he gets that feeling he should not leave his prayer unless he hears the sound (of the air) or smells its odour.” .
وَأَصْلُهُ فِي اَلصَّحِيحَيْنِ مِنْ حَدِيثِ عَبْدِ اَللَّهِ بْنِ زَيْد ٍ 1 .1 - صحيح. ولفظه: شكي إلى النبي صلى الله عليه وسلم: الرجل يخيل إليه أن يجد الشيء في الصلاة؟ قال: "لا ينصرف حتى سمع صوتا، أو يجد ريحا". البخاري (137)، ومسلم (361).
It is originally from the Sahihain of Bukhari and Muslim as the Hadith narrated by ‘Abdullah bin Zaid.