In one sitting we would count the Messenger of Allah ﷺ saying a hundred times: "rabbi ighfir lī wa-tub ʿalayya, innaka anta al-ttawwābu al-raḥīmu (My Lord, forgive me and pardon me for You are the Most Accepting of Repentance and the Most Merciful.)"  

إِنْ كُنَّا لَنَعُدُّ لِرَسُولِ اللَّهِ ﷺ فِي الْمَجْلِسِ الْوَاحِدِ مِائَةَ مَرَّةٍ: (رَبِّ اغْفِرْ لِي وَتُبْ عَلَىَّ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ۔)