"Death and life are in the power of the tongue" (18:21). Does that mean words can kill or give life?

Here is the whole saying: "Death and life are in the power of the tongue; those who love it will eat its fruit" (18:21). In Hebrew in the power of is beyad, in the hand of, with yad, which Brown-Driver-Briggs gives as "hand". The saying doesn't say how the tongue holds death and life. Its second half says who eats the fruit: "those who love it" (18:21). The verse before speaks of fruit too, the fruit of a man's own mouth:"A man’s stomach is filled with the fruit of his mouth. With the harvest of his lips he is satisfied" (18:20). The chapter shows what words do: a fool's mouth is "his destruction" (18:7), and a gossip's words "go down into a person’s innermost parts" (18:8). Other sayings in the book set the two sides out: "There is one who speaks rashly like the piercing of a sword, but the tongue of the wise heals" (Proverbs 12:18), and "A gentle tongue is a tree of life, but deceit in it crushes the spirit" (Proverbs 15:4). The chapter says no more than this about how words bring death or life, and these notes don't either.