"Recite Surat Al-Ikhlas and Al-Mu`awwidhatain (Surat Al-Falaq and Surat An-Nas) three times at dawn and dusk. It will suffice you in all respects" means that then one would not need any other recitation for the remembrance of Allah. Moreover, by virtue of these three Surah, Allah will protect the reciter from every dangerous thing. In other Ahadith, it is stated that after lying in the bed, the Prophet (PBUH) used to recite these Surah, then blow on his hands and rub them over his body to the extent he could.