Even so the tongue is a little member, and boasteth great things. Behold, how great a matter a little fire kindleth! Boasteth great things - That is, can do great things, whether of a good or evil kind. He seems to refer here to the powerful and all commanding eloquence of the Greek orators: they could carry the great mob whithersoever they wished; calm them to peaceableness and submission, or excite them to furious sedition.
Behold, how great a matter - See what a flame of discord and insubordination one man, merely by his persuasive tongue, may kindle among the common people.