أَعُوْذُ بِاللَّهِ مِنَ الشَّيْطَانِ الرَّجِيْمِ

A'oodhu billaahi minash-Shaytaanir-rajeem

I seek refuge in Allah from Satan the outcast. Sulaiman ibn Surad (RA) said: The Messenger of Allah (ﷺ) said: Saying these words will remove the anger of the angry person. We have seen that suppressing anger and forgiving those who are angry is one of the ways to gain Allah's mercy. Therefore, when a believer feels anger, he should say this sentence again and again, looking at the meaning.

Reference: Bukhari: 3282