رَبَّنَآ إِنَّنَآ ءَامَنَّا فَٱغۡفِرۡ لَنَا ذُنُوبَنَا وَقِنَا عَذَابَ ٱلنَّارِ.
Our Lord, indeed we have believed, so forgive us our sins and protect us from the punishment of the Fire.
Rabbana innana amanna faghfir lana dhunubana wa qina adhabannar.
In the Ayah preceding this one, Allah mentions some of the rewards Paradise has in store for the pious (those who have Taqwa). Here, He mentions that these same pious Believers invoke Him with the supplication mentioned above. Hence, it is the pious, or those who refrain from what Allah has forbidden, who will attain His forgiveness and His protection from the Hellfire. This, therefore, excludes those who ask for forgiveness with nothing more than their tongues, and without doing what is required to attain forgiveness. -Tafseer at-Tahreer wa’l-Tanweer.