The Messenger of Allah ﷺ said: My heart is invaded by unmindfulness, and I ask Allah's pardon a hundred times in the day. (Using translation from Abū Dāʾūd 1515)   

قَالَ رَسُولُ اللهِ ﷺ إِنَّهُ لَيُغَانُ عَلَى قَلْبِي وَإِنِّي لَأَسْتَغْفِرُ اللهَ كُلَّ يَوْمٍ مِائَةَ مَرَّةٍ  

[Machine] On the authority of the Prophet Muhammad ﷺ , who said: "O people, turn in repentance to your Lord, for indeed, I turn to Allah in repentance a hundred times every day."  

عَنِ النَّبِيِّ ﷺ أَنَّهُ قَالَ يَا أَيُّهَا النَّاسُ تُوبُوا إِلَى رَبِّكُمْ فَإِنِّي أَتُوبُ إِلَى اللهِ ﷻ كُلَّ يَوْمٍ مِائَةَ مَرَّةٍ