Righteous lips are the delight of kings. The ideal king takes pleasure in the truth and justice which his subjects display in their conversation. Such a one hates flattery and dissimulation, and encourages honest speaking.
They (kings) love him that speaketh right; that which is just (Proverbs 8:6). The two clauses are coordinate. Septuagint, "He loveth upright words" (comp. Proverbs 22:11).