Mishkat al-Masabih 2382, 2383

Hudhayfah reported that when the Prophet ﷺ lay down at night, he would place his hand beneath his cheek and say, “O Allah, in Your name I die and I live.” When he awoke, he would say, “Praise belongs to Allah, who gave us life after causing us to die, and to Him is the resurrection.” Reported by al-Bukhari and Muslim. Both chains are graded Sahih by al-Albani.