Recite Ayat al-Kursi (2:255) — whoever recites it before sleep will have a guard — Sleep Adhkar
آيَةُ الْكُرْسِيِّ: اللَّهُ لَا إِلَهَ إِلَّا هُوَ الْحَيُّ الْقَيُّومُ
Transliteration: Ayat al-Kursi
Translation: Recite Ayat al-Kursi (2:255) — whoever recites it before sleep will have a guardian from Allah, and no devil shall approach them until morning.
Reference: Bukhari 5:297