Dua 63 When a mistake happens (intentionally or unintentionally) or a sin is committed, recite this dua:
(Surah Al-Qasas (28), Verses 15-16)

رَبِّ إِنِّى ظَلَمْتُ نَفْسِى فَٱغْفِرْ لِى

Rabbi innee zalamtu nafsee faghfir lee.

My Lord! I have wronged myself. Forgive me!

(Surah Al-Qasas (28), Verses 16)

One night, Prophet Musa (AS) entered Pharaoh's city and saw two men fighting - one was from his own people (an Israelite). As the Quran states:

هَـٰذَا مِن شِيعَتِهِۦ وَهَـٰذَا مِنْ عَدُوِّهِ

Haazaa min shee'atihee wa haaza min 'aduwwihee.

This one from among his followers, and that one from his enemies.

(Surah Al-Qasas (28), Verses 15)

The follower of Prophet Musa (AS) sought his help. Prophet Musa (AS) intervened to assist him and struck the enemy man with a fist, causing him to die immediately.
Prophet Musa (AS) then said: "This is Satan's doing - he never leaves any excuse for man to go astray." He immediately sought Allah's forgiveness through this dua and prayed for protection, saying: "May the Egyptians not take retaliatory action because of my mistake, or else innocent blood will be shed and believers will be killed."
If any mistake occurs, acknowledge it and ask Allah for forgiveness with this dua. It is a highly beneficial supplication. Allah will protect you from conflicts (and turmoil).