Zayd ibn Arqam reported: The Messenger of Allah, peace and blessings be upon him, said:

اللَّهُمَّ آتِ نَفْسِي تَقْوَاهَا وَزَكِّهَا أَنْتَ خَيْرُ مَنْ زَكَّاهَا

O Allah, grant my soul a sense of righteousness and purify it, for you are the best purifier.

Source: Ṣaḥīḥ Muslim 2722, Grade: Sahih