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
Book 55 · Hadith 75
صحيح مسلم
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