Surah An-Nazi'at 79:18

فَقُلْ هَل لَّكَ إِلَىٰٓ أَن تَزَكَّىٰ

And say to him, 'Would you [be willing to] purify yourself

Translation: Saheeh International

Tafsir

and say “Would you — I call you to — purify yourself tazakkā a variant reading has tazzakkā where the original second tā’ of tatazakkā has been assimilated with the zāy to purge yourself of idolatry by bearing witness that there is no god but God

Excerpt from Tafsir al-Jalalayn, commentary on 79:18, via Quran.com. The reader has the full commentary and 9 more tafsirs.