Narrated Abu Huraira: Allah’s Messenger (?) said,” Whoever says:
“La ilaha illal-lah wahdahu la sharika lahu, lahu-l-mulk wa lahul- hamd wa huwa ‘ala kulli shai'in qadir,” one hundred times will get the same reward as given for manumitting ten slaves; and one hundred good deeds will be written in his accounts, and one hundred sins will be deducted from his accounts, and it (his saying) will be a shield for him from Satan on that day till night, and nobody will be able to do a better deed except the one who does more than he.“
Sahih al-Bukhari 6403
Sahih Muslim 2691
سلسلة الأذكار والأدعية // Athkar & Invocations Series | 21