Bulugh al-Maram #392

Narrated Abu Hurairah (RA) Allah's Messenger (ﷺ) said: "Whoever glorifies Allah (by saying Subhan-Allah) after every Salat (prayer) thirty-three times, and praises Allah (by saying Alhamdu-lillah) thirty-three times, and exalts Allah (by saying Allahu Akbar) thirty-three times, those are ninety-nine in all, and says to complete a hundred: La ilaha ill-Allahu, wahdahu la sharika lahu, lahul-mulku wa lahulhamdu, wa Huwa 'ala kulli shai'in Qadir (There is nothing which deserves to be worshipped except Allah Alone Who has no partner; to Him belongs the kingdom, to Him praise is due, and He has power over everything), his sins will be forgiven, even if they are as abundant as the foam of the sea." .