Solomon
Proverbs 22:11WEB·traditional attribution

He who loves purity of heart and speaks gracefully is the king’s friend.

Geneva Bible Notes Reformed

He that loveth pureness of heart, [for] the grace of his lips the king [shall be] his friend. (g) He shows that princes should use their familiarity, whose conscience is good, and their talk wise and godly.

Keil & Delitzsch Lutheran

Pro 22:11 11 He that loveth heart-purity, Whose is grace of lips, the king is his friend. Thus with Hitzig, it is to be translated not: he who loveth with a pure heart - we may interpret טהור־לב syntactically in the sense of puritate cordis or purus corde (Ralbag, Ewald, after Pro 20:7), for that which follows אהב and is its supplement has to stand where possible as the accus.

John Gill Reformed Baptist

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...