Sahih Muslim — The Book of Zuhd and Softening of Hearts — Hadith No: 7492
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا عَبْدُ الْعَزِيزِ، عَنْ سُهَيْلٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي، سَعِيدٍ عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِذَا تَثَاوَبَ أَحَدُكُمْ فَلْيُمْسِكْ بِيَدِهِ فَإِنَّ الشَّيْطَانَ يَدْخُلُ " .
Translation
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, he should try to restrain it with cue help of his hand since it is the Satan that enters therein