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