عَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ كُنْتُ جَالِسًا عِنْدَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ فَسَمِعْتُهُ اسْتَغْفَرَ مِائَةَ مَرَّةٍ ثُمَّ يَقُولُ اللَّهُمَّ اغْفِرْ لِي وَارْحَمْنِي وَتُبْ عَلَيَّ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ أَوْ إِنَّكَ تَوَّابٌ غَفُورٌ
It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both), he says: I was sitting with the Messenger of Allah (peace and blessings be upon him), I heard him seek forgiveness one hundred times and then make this supplication: "Allahumma ighfir li warhamni, wa tub 'alayya, innaka anta at-Tawwab ar-Raheem." (O Allah! Forgive me, have mercy on me, and turn towards me; surely, You are the Most-Relenting, Most-Merciful.) In one narration, at the end, the words are: "Innaka Tawwabun Ghafoor."