The second type of the types of Tahara is the spiritual one. Just as the clothes of the body are what we wear on us, the clothes of the heart are our souls. It is neither mud nor dust that defiles the garment of the soul; that dirt is Kufr, Shirk, sins, and all kinds of haram.
Water does not help to clean these impurities, the purification of the heart and mind is achieved through repentance. Allah has given good news to those who purify their hearts from diseases and their bodies from impurities: “Successful indeed are those who purify themselves, remember the name of their Lord, and pray.” Surah al-A’la