Yahya related to me from Malik from Sumayy, the mawla of AbuBakr, from Abu Salih as-Samman from Abu Hurayra that the Messenger ofAllah, may Allah bless him and grant him peace, said, "Whoever says,'Glory be to Allah and with His praise' (Subhana'llah wa bi-hamdihi)one hundred times in a day will have his wrong actions taken away fromhim, even if they are as abundant as the foam on the sea."
USC-MSA web (English) reference: Book 15, Hadith 21
Arabic reference: Book 15, Hadith 493