Matthew Henry, on Prov 20:18

Note, 1. It is good in every thing to act with deliberation, and to consult with ourselves at least, and, in matters of moment, with our friends, too, before we determine, but especially to ask counsel of God, and beg direction from him, and observe the guidance of this eye. This is the way to have both our minds and our purposes established, and to succeed well in our affairs; whereas what is done hastily and with precipitation is repented of at leisure. Take time, and you will have done the sooner. Deliberandum est diu, quod statuendum est semel - A final decision should be preceded by mature deliberation. 2. It is especially our wisdom to be cautious in making war. Consider, and take advice, whether the war should be begun or no, whether it be just, whether it be prudent, whether we be a match for the enemy, and able to carry it on when it is too late to retreat (Luk 14:31); and, when it is begun, consider how and by what arts it may be prosecuted, for management is as necessary as courage. Going to law is a kind of going to war, and therefore must be done with good advice, Pro 25:8. The rule among the Romans was nec sequi bellum, nec fugere - neither to urge war nor yet to shun it.