The writer speaks of a person trying to find ways to harm other people as if that person were digging in the ground to find something buried. Alternate translation: "A worthless person looks for mischief as if he were digging for something in the ground" (See: [[rc://en/ta/man/translate/figs-metaphor]])
The writer compares the way this person's words hurt others with the way that fire burns things. Alternate translation: "he hurts people with his words, like a fire scorches the things it touches" (See: [[rc://en/ta/man/translate/figs-simile]])