(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 try to restrain it with cue help of his hand since it is the Satan that enters therein.
Reference: Sahih Muslim 2995 b
In-book reference: Book 55, Hadith 75
USC-MSA web (English) reference(deprecated numbering scheme): Book 42, Hadith 7131