He said: Oh, had you said in the evening: "I take refuge in the perfect words of Allah from the evil of what He created," nothing would have harmed you, Allah willing.
In-book : Book 29, Hadith 44
English translation : Book 28, Hadith 3889
29. Medicine (Kitab Al-Tibb)
باب الاِسْتِتَارِ فِي الْخَلاَءِ