عَنْ أَنَسِ بْنِ مَالِكٍ ‏- رضى الله عنه ‏- قَالَ: { كَانَ أَصْحَابُ رَسُولِ اَللَّهِ ‏- صلى الله عليه وسلم ‏-‏-عَلَى عَهْدِهِ‏- يَنْتَظِرُونَ اَلْعِشَاءَ حَتَّى تَخْفِقَ رُؤُوسُهُمْ, ثُمَّ يُصَلُّونَ وَلَا يَتَوَضَّئُونَ } أَخْرَجَهُ أَبُو دَاوُدَ, وَصَحَّحَهُ اَلدَّارَقُطْنِيّ ُ 1‏ .‏‏1 ‏- صحيح .‏ رواه أبو داود (200)‏، والدارقطني (1/131/3)‏ وقال الدار قطني: صحيح .‏
Translation
Narrated Ibn ‘Abbas (rad)

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.” [Reported by Al-Bazzar].