Verses 27-30 form a group of sayings in that they are warnings to troublemakers.

“A worthless man plots evil”: For “worthless” see 6.12. “Plots” is literally “digs up” and could be related to the metaphor “digging a pit” to trap others. We may say, for example, “Worthless people plan how to harm others” or “Worthless people make schemes to cause trouble for others.” It is also possible to take evil as the goal of the verb “digs up”; so Revised English Bible says “A scoundrel rakes up evil gossip,” and New Living Translation “Scoundrels hunt for scandal.” “Evil” here, as in 11.27, means “trouble,” “misfortune,” or “disaster.”

“And his speech is like a scorching fire”: This line is literally “and on his lips like burning fire.” The sense of the line seems to be that even his speech destroys like a hot fire. “Fire” is a common figure in the Old Testament for destruction. Contemporary English Version has “Even their words burn like a flaming fire.” See Good News Translation also.

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 .