"The Messenger of Allah ﷺ said: 'Whoever says the tasbih one hundred times following the morning prayer, and the tahlil one hundred times, he will be forgiven his sins even if they are like the foam of the sea.'"  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ سَبَّحَ فِي دُبُرِ صَلاَةِ الْغَدَاةِ مِائَةَ تَسْبِيحَةٍ وَهَلَّلَ مِائَةَ تَهْلِيلَةٍ غُفِرَتْ لَهُ ذُنُوبُهُ وَلَوْ كَانَتْ مِثْلَ زَبَدِ الْبَحْرِ