Sahih al-Bukhari 3289
Sahih al-Bukhari · Book 59: Beginning of Creation · The characteristics of Iblis (Satan) and his soldiers
Narrated Abu Huraira:
حَدَّثَنَا عَاصِمُ بْنُ عَلِيٍّ ، حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ ، عَنْ سَعِيدٍ الْمَقْبُرِيِّ ، عَنْ أَبِيهِ ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " التَّثَاؤُبُ مِنَ الشَّيْطَانِ، فَإِذَا تَثَاءَبَ أَحَدُكُمْ فَلْيَرُدَّهُ مَا اسْتَطَاعَ، فَإِنَّ أَحَدَكُمْ إِذَا قَالَ هَا. ضَحِكَ الشَّيْطَانُ " .
The Prophet (ﷺ) said, "Yawning is from Satan and if anyone of you yawns, he should check his yawning as much as possible, for if anyone of you (during the act of yawning) should say: 'Ha', Satan will laugh at him."