Sahih Muslim 362
Sahih Muslim · Book 3: The Book of Menstruation · Evidence that if a person is certain that he is in a state of purity, then he doubts whether he has committed hadith (broken his wudu’), then he prays with his purity like that
Abu Huraira reported:
وَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ ، حَدَّثَنَا جَرِيرٌ ، عَنْ سُهَيْلٍ ، عَنْ أَبِيهِ ، عَنْ أَبِي هُرَيْرَةَ ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا وَجَدَ أَحَدُكُمْ فِي بَطْنِهِ شَيْئًا فَأَشْكَلَ عَلَيْهِ أَخَرَجَ مِنْهُ شَىْءٌ أَمْ لاَ فَلاَ يَخْرُجَنَّ مِنَ الْمَسْجِدِ حَتَّى يَسْمَعَ صَوْتًا أَوْ يَجِدَ رِيحًا " .
The Messenger of Allah (ﷺ) said: If any one of you has pain in his abdomen, but is doubtful whether or not anything has issued from him, be should not leave the mosque unless he hears a sound or perceives a smell.