رَبَّنَا أَتْمِمْ لَنَا نُورَنَا وَاغْفِرْ لَنَا إِنَّكَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
Rabbana atmim lana nurana waighfir lana innaka 'ala kulli shay-in qadir
Our Lord! Perfect our Light for us, and grant us Forgiveness: for Thou hast power over all things. - 66:8
Mujahid states that the Believers will recite this dua at the time when they will see that the celestial light of the Hypocrites had disappeared on the day of Qiyamah.
On the bridge of Sirat the Believers will see (Nur) celestial light in front of them as well as on their right hand side. When they will see that the (Nur) celestial light of the Hypocrites has disappeared they will recite this dua. The (Nur) celestial light will be in proportion to a persons actions. Therefore the dua is being made to perfect the celestial light.
رَبِّ ابنِ لى عِندَكَ بَيتًا فِى الجَنَّةِ
Rabbi ibni lee AAindaka baytan fee aljannati
My Lord! Build for me a home with You in Paradise
Surah At-Tahreem ,verse 11