Sunan Ibn Majah, Book 33, Hadith 162 (In-Book) ⓘ
It was narrated that Hudhaifah said: "I was harsh in the way I spoke to my family, but not to others. I mentioned that to the Prophet (saas) and he said: 'Why don't you ask for forgiveness? Ask Allah to forgive you, seventy times each day.'"
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا أَبُو بَكْرِ بْنُ عَيَّاشٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ أَبِي الْمُغِيرَةِ، عَنْ حُذَيْفَةَ، قَالَ كَانَ فِي لِسَانِي ذَرَبٌ عَلَى أَهْلِي وَكَانَ لاَ يَعْدُوهُمْ إِلَى غَيْرِهِمْ فَذَكَرْتُ ذَلِكَ لِلنَّبِيِّ ـ صلى الله عليه وسلم ـ فَقَالَ " أَيْنَ أَنْتَ مِنَ الاِسْتِغْفَارِ تَسْتَغْفِرُ اللَّهَ فِي الْيَوْمِ سَبْعِينَ مَرَّةً " .
also referenced under: Hadith 3817 (Reference) & Volume 5, Book 33, Hadith 3817 (DarusSalam)