Sunan Ibn Majah, Hadith 3816 ⓘ
It was narrated from Sa'eed bin Abu Burdah bin Abu Musa, from his father, that : his grandfather said: "The Messenger of Allah (saas) said: 'I seek the forgivenenss of Allah and repent to Him seventy times each day.'"
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، عَنْ مُغِيرَةَ بْنِ أَبِي الْحُرِّ، عَنْ سَعِيدِ بْنِ أَبِي بُرْدَةَ بْنِ أَبِي مُوسَى، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " إِنِّي لأَسْتَغْفِرُ اللَّهَ وَأَتُوبُ إِلَيْهِ فِي الْيَوْمِ سَبْعِينَ مَرَّةً " .
also referenced under: Book 33, Hadith 161 (In-Book) & Volume 5, Book 33, Hadith 3816 (DarusSalam)