The yawning as from the devil. So when one of you yawns he should try to restrain it as far as it lies in his power.
Sahih Muslim Book 55, Hadith 73
← Previous Hadith A person sneezed in his presence and he said to him: May Allah have mercy upon you. And he then sneezed for the second time and Allah's Messenger (ﷺ) said to him: He is suffering from cold (and no response is necessary).

Sahih Muslim Book 55, Hadith 72 Next Hadith → 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.

Sahih Muslim Book 55, Hadith 74