Hisn al-Muslim
-- Allah's Messenger (ﷺ) said: "By Allah, I seek the forgiveness of Allah, and repent to Him more than seventy times in a day. Reference: Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 11/101.
قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم: "وَاللَّهِ إِنِّي لأَسْتَغفِرُ اللَّهَ وَأَتُوبُ إِلَيْهِ فِي الْيَوْمِ أَكْثَرَ مِنْ سَبْعِينَ مَرَّةٍ"
Reference