مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 2296
Supplications
The Reward for Glorifying, Praising, Declaring God’s Unity and His Greatness - Section 1
وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: مَنْ قَالَ: سُبْحَانَ اللَّهِ وَبِحَمْدِهِ فِي يَوْمٍ مِائَةَ مَرَّةٍ حُطَّتْ خَطَايَاهُ وَإِنْ كَانَتْ مِثْلَ زَبَدِ الْبَحْرِ
He reported God’s messenger as saying that if anyone says a hundred times in a day, "Glory be to God, and I begin with praise to Him", his sins will be removed from him though they are like the foam of the sea. (Bukhari and Muslim.)
Mishkat al-Masabih, 2296مُتَّفَقٌ عَلَيْهِ (الألباني)