The words we choose can build up or tear down. I have observed just one wrong thought spoken out loud having catastrophic effect. I have also observed one carefully chosen thought, leading to well spoken words, can change a life! One damages the relationship - the other helps it continue to grow. While not all words are worthy of speaking, all thoughts are worthy of careful consideration BEFORE they are spoken. There is another passage in scripture that goes hand in hand with the one above: "There is one whose rash words are like sword thrusts, but the tongue of the wise brings healing." (Proverbs 12:18 ESV) It is oftentimes the "rash words" that bring us the most difficult of circumstances from which we must now "dig out"!
Plato also reminds us: "There is no harm in repeating a good thing." Sometimes it is the repeating of the words until they are well-absorbed that brings the greatest of pleasure and strongest of victories in our lives. We don't always hear what is messaged the first time - even though they are words of great wisdom. Yet, we often take the words of foolishness way too seriously and allow them quicker influence in our lives than we perhaps ought to! We need to weigh carefully the words we say, but equally important is to weigh well the words we absorb into our lives. Just sayin!