Reference : Hisn al-Muslim 86

بِسـمِ اللهِ الذي لا يَضُـرُّ مَعَ اسمِـهِ
شَيءٌ في الأرْضِ وَلا في السّمـاءِ
وَهـوَ السّمـيعُ العَلـيم . (ثلاث مرات)
Bismillāhi ‘l-ladhī lā yaḍurru ma`a-smihi 
shay'un fil-'arḍi wa lā fis-samā' 
wa huwas-Samī `ul-`Alīm.

In the Name of Allah, Who with His Name nothing can cause harm in the earth nor in the heavens, 
and He is the All-Hearing, the All-Knowing. (Recite three times in Arabic).

Reference:
"Whoever recites it three times in the morning will not be afflicted by any 
calamity before evening, and whoever recites it three times in the evening 
will not be overtaken by any calamity before morning." Abu Dawud 4/323, 
At-Tirmidhi 5/465, Ibn Majah 2/332, Ahmad. Ibn Majah's chain of 
transmission is good (Hasan), Ibn Baz, p. 39.

Chapter: In the morning and evening