Yahya related to me from Malik from Sumayy, the mawla of Abu Bakr, from Abu Salih as-Samman from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, said, "Whoever says 'There is no god but Allah, alone, without any partner. The Kingdom and praise belong to Him and He has power over everything' (La ilaha illa'llah, wahdahu la sharika lah, lahu'l mulku wa lahu'l hamd, wa huwa ala kulli shay'in qadir) one hundred times a day, it is the same for him as freeing ten slaves. One hundred good actions are written for him and one hundred wrong actions are erased from him, and it is a protection from Shaytan for that day until the night. No-one does anything more excellent than what he does except someone who does more than that."


حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ سُمَىٍّ، مَوْلَى أَبِي بَكْرٍ عَنْ أَبِي صَالِحٍ السَّمَّانِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَنْ قَالَ لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَىْءٍ قَدِيرٌ فِي يَوْمٍ مِائَةَ مَرَّةٍ كَانَتْ لَهُ عَدْلَ عَشْرِ رِقَابٍ وَكُتِبَتْ لَهُ مِائَةُ حَسَنَةٍ وَمُحِيَتْ عَنْهُ مِائَةُ سَيِّئَةٍ وَكَانَتْ لَهُ حِرْزًا مِنَ الشَّيْطَانِ يَوْمَهُ ذَلِكَ حَتَّى يُمْسِيَ وَلَمْ يَأْتِ أَحَدٌ بِأَفْضَلَ مِمَّا جَاءَ بِهِ إِلاَّ أَحَدٌ عَمِلَ أَكْثَرَ مِنْ ذَلِكَ ‏"‏ ‏.‏
USC-MSA web (English) reference : Book 15, Hadith 20
Arabic reference : Book 15, Hadith 492