Praise be to Allah.
The Prophet (peace and blessings of Allaah be upon him) said: “Whoever says Laa ilaaha ill-Allaah wahdahu laa shareeka lah, lahu’l-mulk wa lahu’l-hamd wa huwa ‘ala kulli shay’in qadeer one hundred times in a day will have (a reward) equivalent to freeing ten slaves, one hundred hasanaat (good deeds) will be recorded for him and one hundred sayi’aat (bad deeds) will be erased from him, and he will be protected from the Shaytaan for that day until evening comes. No one can do anything better than what he has done except one who does more than that. Whoever says Subhaan Allaah wa bi hamdihi (Glory and praise be to Allaah) one hundred times in a day, his sins will be erased even if they were like the foam of the sea.”
Narrated by al-Bukhaari and Muslim.