Whoever says "Glory be to Allah and praise be to Him" one hundred times, his sins will be unloaded from him, even if they were as much as the foam of the sea. [Al-Bukhari]

«مَنْ قَالَ: سُبْحَانَ اللَّهِ وَبِحَمْدِهِ في يومٍ مِائَةَ مَرَّةٍ حُطَّتْ عَنْهُ خَطَايَاهُ وَإِنْ كَانَتْ مِثْلَ زَبَدِ الْبَحْرِ». [متفق عليه]