It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "When one of you yawns, he should cover his mouth, for the devil enters into it."
In another narration from Sayyiduna Abu Sa'id (may Allah be pleased with him), the Prophet (peace and blessings of Allah be upon him) said: "When one of you yawns, he should cover his mouth with his hand, for the devil enters into it."
Hadith Referenceالادب المفرد / كتاب العطاس والتثاؤب / 951
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : صحيح مسلم ، الزهد و الرقائق ، ح : 2995»
Explanation & Benefits
Shaykh Maulana Usman Muneeb
Benefits and Issues: From these narrations, it is understood that yawning is from Shaytan, and Shaytan enters a person’s mouth at the time of yawning and increases laziness and sluggishness in the person, and also manifests his effects. Therefore, along with restraining yawning, one should also cover the mouth with the hand or a cloth, etc.
Source: Fadlullah al-Ahad: Urdu Commentary on al-Adab al-Mufrad, Page: 951