There are forty total Rabbana duas that are mentioned in the Quran. Each of them have their own place and purpose asking Allah for something specific. In this article we will cover the last Rabbana dua which you may know and if you don’t then this article will be worth your time and will help you to learn and memorize it.
The dua I am referring to begins with rabbana atmim lana nurana (rabbana atmim lana noorana). It comes from Surah At-Tahrim verse 8.
rabbana atmim lana noorana full dua with english meaning:
Here is the full dua with Arabic text and translation:
رَبَّنَا أَتْمِمْ لَنَا نُورَنَا وَاغْفِرْ لَنَا إِنَّكَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
Transliteration: Rabbana atmim lana noorana maghfir lana innaka ‘ala kulli shai’in qadeer
English Meaning: “Our Lord, perfect for us our light and forgive us. Indeed, You are over all things competent.”
Translation of the full ayat: Believers, turn to Allah in sincere repentance;  maybe your Lord will expunge your evil deeds and admit you to the Gardens beneath which rivers flow.  This will be on the Day when Allah will not disgrace the Prophet and those who have embraced faith and are with him;  their light will be running before them and on their right hands, and they will say: “Our Lord, perfect for us our light and forgive us. Surely You have power over everything.” 
In  and  it discusses the running of the light before the believers that will be proceeding towards Paradise on the day of resurrection. This is also mentions in verse 12 and 13 or Surah Hadid.
“On the Day you see the believing men and believing women, their light proceeding before them and on their right, [it will be said], “Your good tidings today are [of] gardens beneath which rivers flow, wherein you will abide eternally.” That is what is the great attainment. On the [same] Day the hypocrite men and hypocrite women will say to those who believed, “Wait for us that we may acquire some of your light.” It will be said, “Go back behind you and seek light.” And a wall will be placed between them with a door, its interior containing mercy, but on the outside of it is torment.”
This is Allah’s warning to us, while we are living to turn to Allah and seek ‘sincere repentance’ . Allah is Ar-Rahman (the beneficent) and Ar-Raheem (the merciful) and perhaps to those who are sincere he will relieve us of our evil deed and admit us into Jannah .
Failing to do so, we will become among the one’s who are engulfed with darkness all around us on the day of judgement. From Surah Hadid and this Surah Tahrim Allah tells us the believers are on their way to travelling paradise and will have light. They will hear the screams of the group wailing in the dark. It is because of their past errors and shortcomings and they will be held accountable.
The believers will be terrified, and they will pray: Rabbana atmim lana nurana maghfir lana innaka ‘ala kulli shai’in qadeer, “Our Lord, perfect for us our light, and forgive us. Indeed you are powerful over every thing.”
Ibn Kathir has mentioned about this ayat by saying, when the believers see that the hypocrites have been deprived of the light, they will pray to Allah for the perfection of their light.