مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3906
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah bin Mas'ood said: When the Prophet (ﷺ) went to sleep - Abu Ahmad said: went to his bed - he put his right hand under his cheek - Abu Ahmad said: his right cheek - then he said: “O Allah, protect me from Your punishment on the Day You gather Your slaves together.”
Musnad Ahmad 3931Saheeh because of corroborating evidence. This is a da’eef i