✒ Shayṭān Enters With Yawn
Prophet Muḥammad Ṣallallāhu-ʿAlaihi Wa Sallam said:
إذا تثاءب أحدكم فليضع يده على فيه فإن الشيطان يدخل مع التثاؤب
“When one of you yawns then let him place his hand over his mouth, for indeed Shayṭān (devil) enters (human body) with the yawn.”
● [مختصر صحيح الجامع الصغير برقم ٤٢٦ ، صححه الألباني]
What is worthy of being mentioned here is that al-Ḥāfiẓ Ibn Ḥajr Raḥimahullāh wrote in his book al-Fatḥ that from the characteristics of Prophethood is that the Messenger of Allāh (Ṣallallāhu-ʿAlaihi Wa Sallam) *NEVER YAWNED* in his entire life.
ما تثاءب النبي صلى الله عليه وسلم قط