Verses 23-28 are warnings against evil people who act like friends but are hateful and wicked.

“Like the glaze covering an earthen vessel”: Note that Revised Standard Version and Good News Translation have footnotes on “glaze” and “smooth”. “Glaze” is literally “silver dross,” which is rated as “B” by Hebrew Old Testament Text Project. However, Hebrew Old Testament Text Project admits “glaze” as possibly “a more original text than the Masoretic text, but no ancient textual witness attests it.” According to Whybray, “silver dross” is “a silver-like substance left over from the process of purifying silver and used to cover pottery to make it look like silver.” “Glaze” is a coating of chemicals under heat applied to the surfaces of ceramic vessels to make them resist moisture and give them a glassy surface. “An earthen vessel” refers to a clay pot.

“Are smooth lips with an evil heart”: In this line “smooth”, which follows the Septuagint, is in Hebrew “burning” or “fervent.” Hebrew Old Testament Text Project accepts either the Revised Standard Version “smooth” or “fervent.” Taken as “smooth lips” the sense is, as in Good News Translation, “insincere talk” or “deceptive speech.” Taken as “fervent lips” the idea is “emotional or impassioned speech.” “An evil heart” refers to a person’s thinking or thoughts that are bad or wicked. According to Contemporary English Version, they are “hateful thoughts.” For this whole verse Bible en français courant translates “Warm words that hide a malicious spirit are [like] impure silver that covers clay.” Biblia Dios Habla Hoy says “Smooth words that have evil intention are as a bath of silver on a clay pot.” Another way that this is expressed is “Words that you speak to hide bad things in your thinking are like paint that people put on a cheap earthenware pot to make it look very nice when it is really rubbish.”

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Proverbs. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .