(9) باب تَشْمِيتِ الْعَاطِسِ وَكَرَاهَةِ التَّثَاؤُبِ
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 keep his mouth shut with the help of his hand, for it is the devil that enters therein.
Reference: Sahih Muslim 2995 a
In-book reference: Book 55, Hadith 74
USC-MSA web (English) reference(deprecated numbering scheme): Book 42, Hadith 7130