Bulugh al-Maram 2 The Book of Prayer كتاب الصلاة 117

وَعَنْ أَبِي هُرَيْرَةَ – رضى الله عنه – أَنَّ اَلنَّبِيَّ – صلى الله عليه وسلم -قَالَ : { اَلتَّثَاؤُبُ مِنْ اَلشَّيْطَانِ فَإِذَا تَثَاءَبَ أَحَدُكُمْ فَلْيَكْظِمْ مَا اِسْتَطَاعَ } رَوَاهُ مُسْلِمٌ 1 1 – صحيح . رواه مسلم (2994) .

Narrated Abu Hurairah (RA): The Prophet (صلى الله عليه وسلم) said: “Yawning is caused by the devil, so when one of you yawns he must repress it as much as he can.” [Reported by Muslim].