Mahatma Gandhi says that “True beauty consists in purity of heart.”
The definition of purity is: freedom from adulteration or contamination. Like in "the purity of our drinking water"
Freedom from immorality, especially of a sexual nature.
Virtue, morality, goodness, righteousness, saintliness, piety, honor, honesty, integrity, decency, ethicality, impeccability;
Blessed are the pure in heart. That is, “whose minds, motives, and principles are pure. Who seek not only to have the external actions correct, but who desire to be holy in heart, and who are so. Man looks on the outward appearance, but God looketh on the heart.” Barnes' Notes on the New Testament