Ayat al-Kursi before sleep
إِذَا أَوَيْتَ إِلَى فِرَاشِكَ فَاقْرَأْ آيَةَ الْكُرْسِيِّ، فَإِنَّهُ لَنْ يَزَالَ عَلَيْكَ مِنَ اللَّهِ حَافِظٌ، وَلَا يَقْرَبَكَ شَيْطَانٌ حَتَّى تُصْبِحَ
Idha awayta ila firashika fa-qra' ayata-l-kursiyy, fa-innahu lan yazala alayka mina-llahi hafidh, wa la yaqrabaka shaytanun hatta tusbih.
"When you go to your bed, recite Ayat al-Kursi. A guardian from Allah will be with you, and Satan will not come near you until morning."
Narrated by Abu Hurayrah. Sahih al-Bukhari 2311
A short reflection
The story is famous: Abu Hurayrah catches a thief stealing zakat. The thief teaches him this verse. The thief turns out to be Shaytan. The Prophet ﷺ confirms: he taught you the truth, even though he is a liar.