37:81
إِنَّهُۥ مِنْ عِبَادِنَا ٱلْمُؤْمِنِينَ ٨١
Saheeh International
Indeed, he was of Our believing servants.
Tafsir of "Ibn Kathir" (English)
Verily, he (Nuh) was one of Our believing servants.meaning, one of the sincere believers in the Oneness of Allah, one of those who had certain faith.ثُمَّ أَغْرَقْنَا الاْخَرِينَ