They will suffice him (as a protection) against everything

{ Qul huwa Allahu Ahad…} [Al-Ikhlas]
{ Qul auoodhu bi Rabbi alFalaq…..} [Al-Falaq]
{ Qul auoodhu bi Rabbi alNnas…..} [An-Nas]

Whoever recites these three times in the morning and in the evening, they will suffice him (as a protection) against everything.

The hadith was reported by Abu Dawood 4/322, and At-Tirmidhi 5/567. See Al-Albanee’s Saheeh At-Tirmidhi 3/182