Riyad as-Salihin: The Book of the Remembrance of Allah – Hadith No. 779 — Hudhaifah and Abu Dharr (May Allah be pleased with him) reported: The Messenger… (Hadith No. 779)

Hudhaifah and Abu Dharr (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) used to supplicate when he went to bed at night: "Bismik-Allahumma ahya wa amut (With Your Name, O Allah, I expire and return to life).".

Explanation:

Reference: Riyad as-Salihin, The Book of the Remembrance of Allah, Hadith No. 779