It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that when the Prophet (peace and blessings be upon him) would lie down on his bed, he would place his right hand under his cheek and recite this supplication: «اللّٰهُمَّ قِنِي عَذَابَكَ يَوْمَ تَبْعَثُ عِبَادَكَ» "O Lord! Save me from the punishment of the Day when You will gather Your servants."