כֶּ֣סֶף סִ֭יגִים מְצֻפֶּ֣ה עַל־חָ֑רֶשׂ שְׂפָתַ֖יִם דֹּלְקִ֣ים וְלֶב־רָֽע׃
Burning lips and a wicked heart Are like an earthen vessel overlaid with silver dross.
Read kabbalistic (mystical) interpretation of Proverbs 26:23: and classical mystical sources.