(Al-Muaminoon) 23 : 109
إِنَّهُ كَانَ فَرِيقٌ مِنْ عِبَادِي يَقُولُونَ رَبَّنَا آمَنَّا فَاغْفِرْ لَنَا وَارْحَمْنَا وَأَنْتَ خَيْرُ الرَّاحِمِينَ
Indeed, there was a portion of My servants who prayed: “Our Lord, indeed we have believed, so You forgive us and shower Mercy upon us, and You are the Best among the merciful”.
See explanation 9: 112 and 21: 83-86.