It is narrated from Hazrat Hafsa that when the Prophet (peace be upon him) would come to his bed, he would lie down placing his right hand under his right cheek, then he would recite this supplication: "O Lord, save me from the punishment of the Day when You will gather Your servants." He would recite this supplication three times. And it was the practice of the Prophet (peace be upon him) to use his right hand for eating and drinking, and to use his left hand for other purposes.
Hadith Referenceمسند احمد / مسند النساء / 26465
Hadith Gradingحکم دارالسلام:إسناده ضعيف لجهالة حال سواء الخزاعي وانقطاع بين عاصم و سواء الخزاعي، وعاصم تكلموا فى حفظه، وقد اضطرب فى هذا الإسناد