Not graded
Hisn al-Muslim (Fortress of the Muslim) 57
((اللَّهُمَّ إِنِّي ظَلَمْتُ نَفْسِي ظُلْماً كَثِيراً، وَلاَ يَغْفِرُ الذُّنوبَ إِلاَّ أَنْتَ، فَاغْفِرْ لِي مَغْفِرَةً مِنْ عِنْدِكَ وَارْحَمْنِي، إِنَّكَ أَنْتَ الغَفورُ الرَّحيمُ)).
(O Allah, I have indeed oppressed my soul excessively and none can forgive sin except You, so forgive me a forgiveness from Yourself and have mercy upon me. Surely, You are The Most-Forgiving, The Most-Merciful.)(From Yourself: i.e. from Your innermost grace without deserving it and a forgiveness which is befitting to your tremendous generosity.)
Cited in Hisn al-Muslim (Fortress of the Muslim) (No. 57).