Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:80:3 –

But what would make you perceive, ˹O Muhammad˺, that perhaps he might be purified  

And how would you know? Perhaps he would cleanse himself (yazzakkā: the original tā’ ˹of yatazakkā˺ has been assimilated with the zāy), that is, ˹perhaps˺ he would purge himself of sins by what he hears from you,
القرآن:٨٠:٣ –

وَمَا يُدْرِيكَ لَعَلَّهُ يَزَّكَّىٰ  

{وما يُدريك} يعلمك {لعله يزكى} فيه إدغام التاء في الأصل في الزاي، أي يتطهر من الذنوب بما يسمع منك.