Sahih Bukhari Volume 4, Book 59, Hadith 3276

وَقَالَ عُثْمَانُ بْنُ الْهَيْثَمِ حَدَّثَنَا عَوْفٌ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ وَكَّلَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم بِحِفْظِ زَكَاةِ رَمَضَانَ، فَأَتَانِي آتٍ، فَجَعَلَ يَحْثُو مِنَ الطَّعَامِ، فَأَخَذْتُهُ فَقُلْتُ لأَرْفَعَنَّكَ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم‏.‏ فَذَكَرَ الْحَدِيثَ فَقَالَ إِذَا أَوَيْتَ إِلَى فِرَاشِكَ فَاقْرَأْ آيَةَ الْكُرْسِيِّ لَنْ يَزَالَ عَلَيْكَ مِنَ اللَّهِ حَافِظٌ، وَلاَ يَقْرَبُكَ شَيْطَانٌ حَتَّى تُصْبِحَ‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ صَدَقَكَ وَهْوَ كَذُوبٌ، ذَاكَ شَيْطَانٌ ‏"

Narrated Muhammad bin Sirin: Abu Huraira said, "Allah's Apostle put me in charge of the Zakat of Ramadan (i.e. Zakat-ul-Fitr). Someone came to me and started scooping some of the foodstuff of (Zakat) with both hands. I caught him and told him that I would take him to Allah's Apostle." Then Abu Huraira told the whole narration and added "He (i.e. the thief) said, 'Whenever you go to your bed, recite the Verse of "Al-Kursi" (2.255) for then a guardian from Allah will be guarding you, and Satan will not approach you till dawn.' " On that the Prophet said, "He told you the truth, though he is a liar, and he (the thief) himself was the Satan."