For seeking forgiveness of sins (Dua in Sajdah)

The most beloved one of Allah is he who often makes prostration and therein recites the following Doas.

رَبِّ إِنِّي ظَلَمْتُ نَفْسِيْ فَاغْفِرْ لِيْ اِنَّهٗ لَا يَغْفِرُ الذُّنُوْبَ اِلاَّ اَنْتَ.

Transliteration:

"Rabbe innee zalamto nafsee faghfir lee innahu laa yaghferuz zonooba illaa anta."

Translation:

"O My Lord! Verily I have been unjust to myself So forgive me (for it) Indeed none pardons the sins except Thee."