رَبَّنَا ظَلَمْنَا أَنفُسَنَا وَإِن لَّمْ تَغْفِرْ لَنَا وَتَرْحَمْنَا لَنَكُونَنَّ مِنَ الْخَاسِرِينَ
"Our Lord, we have wronged ourselves, and if You do not forgive us and have mercy upon us, we will surely be among the losers."
This dua of the Quran is mentioned in Surah Aaraf Ayah No. 23.
This is the supplication of Prophet Adam and Hawwa (as). The background of this dua is that Allah Almighty accommodated them in Paradise and asked them not to approach a particular tree but Satan whispered in their hearts and misguided them and persuaded them to make mistake with his trick and finally Prophet Adam and Hawwa (as) tasted the fruit of forbidden tree, consequently for punishment they were unclothed then Allah said to them “Did I not forbid you from that tree and did I not tell you that Satan is your open enemy?”. Then they realized their mistakes and sought forgiveness from Allah with this dua.
Satan was able to misguide even prophet then where do we stand? So, we should keep seeking Allah’s mercy and forgiveness through this dua.