Solomon
Proverbs 22:11ESV·traditional attribution

He who loves purity of heart, and whose speech is gracious, will have the king as his friend.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. The qualification of an accomplished, a complete gentleman, that is fit to be employed in public business. He must be an honest man, a man that loves pureness of heart and hates all impurity, not only pure from all fleshly lusts, but from all deceit and dissimulation, from all selfishness and sinister designs, that takes care to approve himself a man of...

John Gill Reformed Baptist @doctorgill

He that loveth pureness of heart,.... Though man's heart is naturally impure, and all that is in it, the thoughts, affections, mind, conscience, understanding, and will; yet there is such a thing as pureness of heart; as where the grace of God is; where there it pure love to God, Christ, and to holy and heavenly things and persons; where there is pure and unfeigned...

Jamieson-Fausset-Brown Reformed @jfbcommentary

(Compare Margin). pureness of heart--and gentle, kind words win favor, even from kings.