Sahih al-Bukhari 5010

Narrated Abu Huraira:Allah's Messenger (ﷺ) ordered me to guard the Zakat revenue of Ramadan. Then somebody came to me and started stealing from the foodstuff. I caught him and said, "I will take you to Allah's Messenger (ﷺ)!" Then Abu Huraira described the whole narration and said: That person said (to me), "(Please don't take me to Allah's Messenger (ﷺ) and I will tell you a few words by which Allah will benefit you.) When you go to your bed, recite Ayat-al-Kursi, (2.255) for then there will be a guard from Allah who will protect you all night long, and no Satan will come near you until the morning.." (When the Prophet (ﷺ) heard the story) he said (to me), "He (who came to you at night) told you the truth although he is a liar; and it was a Satan."