Hadith #5045 (Sunan Abi Dawud)
Book: General Behavior (Kitab Al-Adab)
Narrator(s): al-Bara' bin Azib bin al-Harith, Fatr bin Khalifa فطر بن خليفة, Masdad bin Masrhad مسدد بن مسرهد بن مسربل, Sa'd bin 'Ubaida al-Salmi سعد بن عبيدة السلمي أبو حمزة, Yahya bin Sa'id bin Farroukh al-Qatan يحيى بن سعيد بن فروخ القطان
Grade: Sahih

When the Messenger of Allah (ﷺ) wanted to go to sleep, he put his right hand under his cheek and would then say three times: O Allah, guard me from Thy punishment on the day when Thou raisest up Thy servants.

Source: https://parallelquran.com/hadith/sunan-abi-dawud-5045/