I learned as a child this little ditty:

“Sticks and stones may break my bones,
but names will never hurt me.”

The intent was good — to deflect unkind words. The truthfulness of the ditty, however, questionable. What is said can have potent, life-altering impact. And James knows that. Notice these words from James 3:

3 When we put bits into the mouths of horses to make them obey us, we can turn the whole animal. 4 Or
take ships as an example. Although they are so large and are driven by
strong winds, they are steered by a very small rudder wherever the
pilot wants to go. 5 Likewise
the tongue is a small part of the body, but it makes great boasts.
Consider what a great forest is set on fire by a small spark. 6 The
tongue also is a fire, a world of evil among the parts of the body. It
corrupts the whole person, sets the whole course of his life on fire,
and is itself set on fire by hell.

7 All kinds of animals, birds, reptiles and creatures of the sea are being tamed and have been tamed by man, 8 but no man can tame the tongue. It is a restless evil, full of deadly poison.

The point for James is not simply to marvel at the astounding difference between little item and big impact, though that is the avenue he walks. No, his point is to focus on the astounding difference in order to motivate the teachers (1) to recognize the impact of the tongue and (2) to alter their behavior in order to use the tongue properly — to do with it what God designed it to do.

Horse bits and ship rudders (see picture) and small spark — control the horse, guide the ship, and turn a forest aflame.

Tongue — boasting and destructive. That is the focus of James.