Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Whoever recites 'Subhan Allah' 33 times after every prayer, recites 'Al-hamdu lillah' 33 times, and recites 'Allahu akbar' 33 times, so that their number reaches 99, and then, to complete 100, recites: 'There is no god except Allah Almighty, He alone is the only one worthy of worship, He has no partner; the dominion belongs to Him alone, and praise belongs to Him alone, and He has power over all things' (the Prophet (peace and blessings be upon him) says:) then that person's sins will be forgiven, even if they are like the foam of the sea."
(Allamah al-Haythami says:) I say:
This narration is reported in the Sahih in abridged form.
Ahmad recorded it, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأذكار / 16915
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه احمد فى المسند (471/2) ، أخرجه صحيح مسلم برقم: 939، وأخرجه مسند أحمد برقم: 8616»