Talking about every little irritation or piece of gossip only keeps the fires of anger going. Refusing to discuss them cuts the fuel line and makes the fires die out. Does someone continually irritate you? Decide not to complain about the person and see if your irritation dies from lack of fuel.
This is just saying, stop adding fuel to the fire and the fire will die down. A rumor cannot damage anyone until it is told, Gossip is like the wood. It causes widespread damage. To stop the damage, stop the gossip. This continues in the next verse.
We see there, a situation where the coals of gossip have just about gone out, but a contentious man who loves trouble will go in there and rekindle the mess all over again. To make coals re-ignite you blow on them and add a little kindling (gossip), to the fire. This makes an even hotter fire than you had in the first place. This evil man wants to keep the quarrel going so he stirs it up a little and gets it going full blast again.
Under Gods command 