Here is, 1. The good character of a wise and virtuous man implied. He is one that has rule over his own spirit; he maintains the government of himself, and of his own appetites and passions, and does not suffer them to rebel against reason and conscience.
He has the rule of his own thoughts, his desires, his inclinations, his resentments, and keeps them all in good order. 2. The bad case of a vicious man, who has not this rule over his own spirit, who, when temptations to excess in eating or drinking are before him, has no government of himself, when he is provoked breaks out into exorbitant passions, such a one is like a city that is broken down and without walls.
All that is good goes out, and forsakes him; all that is evil breaks in upon him. He lies exposed to all the temptations of Satan and becomes an easy prey to that enemy; he is also liable to many troubles and vexations; it is likewise as much a reproach to him as it is to a city to have its walls ruined, Nehemiah 1:3.