O Allah, Shield Me From Your Punishment
Say 3 times
اللَّهُمَّ قِنِي عَذَابَكَ يَوْمَ تَبْعَثُ عِبَادَكَ
Allahumma qini 'adhabaka yawma tab'athu 'ibadak.
O Allah, shield me from Your punishment on the Day You raise Your servants.
What it means
A single request, made at the moment you are least in control of yourself. Going to sleep with the Day of Resurrection on your mind is a gentle way of keeping it in view without fear taking over.
When and how
Say it three times as you settle down to sleep, with your right hand under your cheek.
Its virtue
The Prophet ﷺ would place his right hand under his cheek and say this three times when he wanted to sleep, reported in Sunan Abi Dawud 5045 and Jami at-Tirmidhi 3398.
Source
Abu Dawud 5045; At-Tirmidhi 3398sahih