Faith
مَنْ قَالَ: لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ، فِي يَوْمٍ مِائَةَ مَرَّةٍ، كَانَتْ لَهُ عَدْلَ عَشْرِ رِقَابٍ
Translation
Whoever says "There is no god but Allah alone, He has no partner, to Him belongs the dominion and to Him belongs all praise, and He is able to do all things" one hundred times in a day, it will be equivalent to freeing ten slaves.
Narrator
Abu Hurairah
Source
Sahih Bukhari & Muslim
Bukhari 3293, Muslim 2691