صحیح ابن حبان
Ibn Hibban
كتاب الرقائق
Book of Heart-Softeners
باب الأذكار - ذكر مغفرة الله جل وعلا ما قدم من ذنوب العبد بقوله سبحان الله وبحمده بعدد معلوم عند الصباح والمساء
Chapter on Remembrance – On Allah’s forgiveness for past sins for saying “Subhan Allah wa bihamdih” a certain number of times morning and evening
1 hadith
Hadith 859
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Whoever recites «سبحان الله و بحمده» one hundred times in the morning and also recites these words one hundred times in the evening, his sins will be forgiven, even if they are more than the foam of the sea."