5 Even so the tongue is a little member, and boasteth great things. Behold, how great a matter  a little fire kindleth!
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.
5 So also the tongue is a small member, yet it boasts of great things. How great a forest is set ablaze by such a small fire!
5 A word out of your mouth may seem of no account, but it can accomplish nearly anything - or destroy it!
5 Even so the tongue is a little member and boasts great things. See how great a forest a little fire kindles!
5 In the same way, the tongue is a small thing that makes grand speeches. But a tiny spark can set a great forest on fire.
Matthew Henry's Commentary on James 3:5
Commentary on James 3:1-12
(Read James 3:1-12)
We are taught to dread an unruly tongue, as one of the greatest evils. The affairs of mankind are thrown into confusion by the tongues of men. Every age of the world, and every condition of life, private or public, affords examples of this. Hell has more to do in promoting the fire of the tongue than men generally think; and whenever men's tongues are employed in sinful ways, they are set on fire of hell. No man can tame the tongue without Divine grace and assistance. The apostle does not represent it as impossible, but as extremely difficult. Other sins decay with age, this many times gets worse; we grow more froward and fretful, as natural strength decays, and the days come on in which we have no pleasure. When other sins are tamed and subdued by the infirmities of age, the spirit often grows more tart, nature being drawn down to the dregs, and the words used become more passionate. That man's tongue confutes itself, which at one time pretends to adore the perfections of God, and to refer all things to him; and at another time condemns even good men, if they do not use the same words and expressions. True religion will not admit of contradictions: how many sins would be prevented, if men would always be consistent! Pious and edifying language is the genuine produce of a sanctified heart; and none who understand Christianity, expect to hear curses, lies, boastings, and revilings from a true believer's mouth, any more than they look for the fruit of one tree from another. But facts prove that more professors succeed in bridling their senses and appetites, than in duly restraining their tongues. Then, depending on Divine grace, let us take heed to bless and curse not; and let us aim to be consistent in our words and actions.