Not graded
Mishkat al-Masabih 6247
وَعنهُ قا ل: اسْتَغْفَرَ لِي رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ خمْسا وَعشْرين مرّة. رَوَاهُ التِّرْمِذِيّ
He told that God's messenger asked forgiveness for him twenty-five times. Tirmidhi transmitted it.
Cited in Mishkat al-Masabih (No. 6247).