لَا إِلَهَ إِلَّا اللهُ ، وَحْدَهُ لَا شَرِيكَ لَهُ ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ ، يُحْيِي وَيُمِيتُ ، وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
Translation 
The messenger of Allah (may the peace and blessings of Allah be upon him) said: Whoever says (translation of which is):
"None has the right to be worshipped except Allah, alone, without partner, to Him belongs all sovereignty and praise, He gives life and causes death and He is over all things omnipotent."
ten times is like the one who had freed four souls from among the children of Ismaa'eel.
[In another narration: "who ever says it after Maghrib prayer, Allah will send guardians (i.e. angels) to protect him (or her) from Shaytan until the morning, and will gain ten rewards and get ten bad deeds wiped off of his record"]
*Supplicate ten times in the evening (after the Asr or Maghrib) and in the morning (after Fajr prayers)
"None has the right to be worshipped except Allah, alone, without partner, to Him belongs all sovereignty and praise, He gives life and causes death and He is over all things omnipotent."
ten times is like the one who had freed four souls from among the children of Ismaa'eel.
[In another narration: "who ever says it after Maghrib prayer, Allah will send guardians (i.e. angels) to protect him (or her) from Shaytan until the morning, and will gain ten rewards and get ten bad deeds wiped off of his record"]
*Supplicate ten times in the evening (after the Asr or Maghrib) and in the morning (after Fajr prayers)
Transliteration
laa ilaaha ill-allaahu, waḥdahu laa shareeka lahu, lahul-mulku wa lahul-ḥamdu, yuḥyee wa yumeetu, wa huwa ‛alaa kulli shay’in qadeer
Sources:
At-Tirmidhi No# 3534 and 3553
