It is reported that Sayyiduna ‘Ali Radhiyallahu Anhu used to say: “I cannot understand how any intelligent Muslim would go to bed without reciting Ayatul Kursi.” [Azkar – page 80]
It is narrated in another Hadith that, if a person recites Ayatul Kursi at bedtime, an Angel will be appointed to protect him, and Shaytaan will not be able to approach him until morning. Whoever recites Ayatul Kursi while lying on his bed - he will be in Allah’s protection, and even the surrounding homes [neighbours] will be protected. [Marginal notes of Hisn Hasin, page 139]
Note: The recital of Ayatul Kursi – especially at bedtime – wards off many misfortunes, including the whisperings of Shaytaan and black magic. Women especially should regard it as compulsory upon themselves to recite it together with the Mu’awwathatayn every night.
[The Sublime Conduct of Nabi Sallallahu Alayhi Wasallam – by Mufti Muhammad Irshad Ahmed Qasim mudda zilluhu]