From Sahih Bukhari (Hadith 7394):
Narrated Hudhaifah:When the Prophet (ﷺ) went to bed, he used to say, "Allahumma bismika ahya wa amut." And when he woke up in the mornings he used to say, "Al-hamdu li l-lahi al-ladhi ahyana ba'da ma amatana wa ilaihi-nnushur
Reference: Bukhari 7394