Sahih Muslim 7493
صحيح مسلم#7493Sahihحَدَّثَنِي أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعٌ، عَنْ سُفْيَانَ، عَنْ سُهَيْلِ بْنِ أَبِي صَالِحٍ، عَنِ ابْنِ أَبِي سَعِيدٍ الْخُدْرِيِّ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا تَثَاوَبَ أَحَدُكُمْ فِي الصَّلاَةِ فَلْيَكْظِمْ مَا اسْتَطَاعَ فَإِنَّ الشَّيْطَانَ يَدْخُلُ " .
The son of Abu Said al-Khudri reported on the authority of his father that Allah's Messenger (ﷺ) said. When one of you yawns while engaged in prayer, he should try to restrain so far as it lies in his power, since it is the Satan that enter therein
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 55:76