Behold, we put bits in the horses' mouths
By this, and the following simile, the apostle not only expresses the smallness of that member of the body, which is like the bit in the horse's mouth, and the helm of a ship, but the good use of it, and the great influence it has over the whole body. Horses are without understanding, and need direction in what path to go, and are strong, and would be truly and ungovernable unless bits and bridles were put into their mouths:
that they may obey us;
and go in the way we would have them:
and we turn about the whole body
of the horse, this way, and that way, as is thought best, by the help of the bit and bridle; and of such use is the tongue to the natural body, that being bridled itself, bridles, directs, and governs the whole body; and its influence on bodies, and societies of men, and Christians, is like that of the bit in the horse's mouth; who, like horses, would be unruly and ungovernable, were it not for the force of language, the power of words, and strength of argument.