Narrated Abu Huraira: Allah's Messenger (ﷺ) deputed me to keep Sadaqat (al-Fitr) of Ramadan. Acomer came and started taking handfuls of the foodstuff (of theSadaqa) (stealthily). I took hold of him and said, "By Allah, I willtake you to Allah's Messenger (ﷺ) ." He said, "I am needy and have manydependents, and I am in great need." I released him, and in themorning Allah's Messenger (ﷺ) asked me, "What did your prisoner doyesterday?" I said, "O Allah's Messenger (ﷺ)! The person complained of beingneedy and of having many dependents, so, I pitied him and let him go."Allah's Messenger (ﷺ) said, "Indeed, he told you a lie and he will be comingagain." I believed that he would show up again as Allah's Messenger (ﷺ) hadtold me that he would return. So, I waited for him watchfully. When he(showed up and) started stealing handfuls of foodstuff, I caught holdof him again and said, "I will definitely take you to Allah's Messenger (ﷺ).He said, "Leave me, for I am very needy and have many dependents. Ipromise I will not come back again." I pitied him and let him go.In the morning Allah's Messenger (ﷺ) asked me, "What did your prisoner do."I replied, "O Allah's Messenger (ﷺ)! He complained of his great need and oftoo many dependents, so I took pity on him and set him free." Allah'sApostle said, "Verily, he told you a lie and he will return." I waitedfor him attentively for the third time, and when he (came and) startedstealing handfuls of the foodstuff, I caught hold of him and said, "Iwill surely take you to Allah's Messenger (ﷺ) as it is the third time youpromise not to return, yet you break your promise and come." He said,"(Forgive me and) I will teach you some words with which Allah willbenefit you." I asked, "What are they?" He replied, "Whenever you goto bed, recite "Ayat-al-Kursi"-- 'Allahu la ilaha illa huwa-l-Haiy-ulQaiyum' till you finish the whole verse. (If you do so), Allah willappoint a guard for you who will stay with you and no satan will comenear you till morning. " So, I released him. In the morning, Allah'sApostle asked, "What did your prisoner do yesterday?" I replied, "Heclaimed that he would teach me some words by which Allah will benefitme, so I let him go." Allah's Messenger (ﷺ) asked, "What are they?" Ireplied, "He said to me, 'Whenever you go to bed, recite Ayat-al-Kursifrom the beginning to the end ---- Allahu la ilaha illahuwa-lHaiy-ul-Qaiyum----.' He further said to me, '(If you do so),Allah will appoint a guard for you who will stay with you, and nosatan will come near you till morning.' (Abu Huraira or anothersub-narrator) added that they (the companions) were very keen to dogood deeds. The Prophet (ﷺ) said, "He really spoke the truth, although heis an absolute liar. Do you know whom you were talking to, these threenights, O Abu Huraira?" Abu Huraira said, "No." He said, "It wasSatan."