Loose lips sink ships. This was a saying used during WWII to speak of the need to be careful of what someone said - because if the enemy were to gain knowledge - it might result in the sinking of one of our vessels as it was in the European theater of the war. This saying could be changed to "loose lips, sink lives," according to the proverb today. Let's take a closer look and see why this is so.
The one who is "guarding" his lips is the one who watches over what comes out of them. He keeps himself from speaking outside of what God wants to be said. He sets a guard over his lips so that he does what Joshua was told in the first chapter of the book using his name. Do not let the book of the law depart from your mouth. The wise man in guarding his mouth - also is guarding and preseving his very life. There are so many ways that our mouths can get us in trouble. Think about the number of times we've seen public figures not watch their mouths and pay for it dearly when things were said that ruined them. Remember Jesus said that it is out of the abundance of the heart that the mouth speaks. So what comes out of our mouths reflects what truly is in our hearts. That is why it is so vital that we guard what actually comes out of them.
The proverb also deals with the person who says that they can say whatever they want. This is true, but there is a cost for this kind of attitude. That cost is ruin. The word means to be destroyed, to be ruined. It also has the idea of terror and fear. We may think we can say anything we want - but the fact is that when truly stupid statements are made - the devastation they render can be terrifying. You can watch someone fall from tremendous heights of power and public opinion in a matter of hours when their mouths are not guarded in what they say.
The guarded mouth is the wise mouth. We all have things we want to say - but we know that such things often are better left unsaid - and honestly - repented of in our hearts. To leave our mouths without any kind of guard or watch is like leaving a post in battle unguarded. It will lead to ruin.