Abdur Rahman bin Abi Saeed narrated from his father that the Messenger of Allah (peace be upon him) said: "When any of you yawns, he should place his hand over his mouth, for the devil enters the mouth." Imam Darimi (may Allah have mercy on him) said: That is, he should place his hand over his mouth.
Hadith Referenceسنن دارمي / من كتاب الصللاة / 1420
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده حسن من أجل نعيم بن حماد، [مكتبه الشامله نمبر: 1422]
Hadith Takhrijاس روایت کی سند حسن ہے، لیکن دوسری سند سے حدیث صحیح ہے۔ دیکھئے: [مسلم 2995] ، [أبوداؤد 5026، 5027] ، [أبويعلی 1162] ، [ابن حبان 2360]