Mishkat al-Masabih
Abu Huraira reported God’s messenger as saying, “I swear by God that I ask God’s pardon and turn to him in repentance more than seventy times a day.” Bukhari transmitted it.
عَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «وَاللَّهِ إِنِّي لِأَسْتَغْفِرُ اللَّهَ وَأَتُوبُ إِلَيْهِ فِي الْيَوْمِ أَكْثَرَ مِنْ سبعينَ مرَّةً» . رَوَاهُ البُخَارِيّ
Reference