"We used to count that the Messenger of Allah ﷺ said one hundred times in a gathering: 'Rabbighfirli wa tub ʿalayya innaka Antat-Tawwabur-Rahim (O Allah forgive me and accept my repentance, for You are the Accepter of repentance, the Most Merciful).'"  

إِنْ كُنَّا لَنَعُدُّ لِرَسُولِ اللَّهِ ﷺ فِي الْمَجْلِسِ يَقُولُ رَبِّ اغْفِرْ لِي وَتُبْ عَلَىَّ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ مِائَةَ مَرَّةٍ  

We counted that the Messenger of Allah ﷺ would say a hundred times during a meeting: "My Lord, forgive me and pardon me; Thou art the Pardoning and forgiving One". (Using translation from Abū Dāʾūd 1516)   

رُبَّمَا أَعُدُّ لِرَسُولِ اللَّهِ ﷺ فِي الْمَجْلِسِ الْوَاحِدِ مِائَةَ مَرَّةٍ «رَبِّ اغْفِرْ لِي وَتُبْ عَلَيَّ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ»  

[Machine] I heard the Messenger of Allah ﷺ in a gathering seeking forgiveness from Allah a hundred times, saying, "O Allah, forgive me, have mercy on me, and accept my repentance. Indeed, You are the Accepter of repentance, the Merciful."  

سَمِعْتُ رَسُولَ اللهِ ﷺ فِي مَجْلِسٍ يَسْتَغْفِرُ اللهَ مِائَةَ مَرَّةٍ يَقُولُ «رَبِّ اغْفِرْ لِي وَارْحَمْنِي وَتُبْ عَلَيَّ؛ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ»  

"رَبِّ اغْفِرْ لِى وَتُبْ عَلَىَّ إِنَّكَ أَنْتَ التَّوَّابُ الْغَفُورُ".