Proverbs 16:22 (ESV) … “Good sense is a fountain of life to him who has it, but the instruction of fools is folly.”
Proverbs is filled with wise words about the tongue. This text has a cluster of sayings about wise use of speech, but our text is only a sample of many more sayings on the same subject. If a subject in the Bible appears often, what is the Bible telling us? Now turn that question over. If the Bible mentions an idea but once, twice, what does that mean? The obvious answer to my questions is that if the Bible returns to an idea repeatedly, the Bible is telling us that the idea is important. If an idea is mentioned rarely, then it is not as important.
This is the fourth and final reference to in Proverbs to ‘a fountain of life’. This description is elsewhere attributed to ‘the mouth of the righteous’ (10:11); ‘the teaching of the wise’ (13:14) and ‘the fear of the Lord’ (14:27), which, of course, is the beginning of wisdom.
Here it is ‘understanding’ that is ‘a fountain of life’, which suggests liveliness and life.
Solomon and his first readers knew what it was for there to be a shortage of water, and the picture of fresh, bubbling water is a powerful one. Here the contrast is with ‘folly’, which is all that fools have. It amuses them for a while (see 15:21) but not for ever. We have already learned that folly leads astray and is loud, deceitful, unproductive and quick-tempered (5:23; 9:13; 12:23; 13:16; 14:4, 8, 29). Here its power to bring ‘punishment to fools’ is underlined.
A great example of this Proverb is to look back and remember when Franklin D. Roosevelt began what he called “fireside chats.” The country was in trouble. People were afraid. Then, a man with a pleasant voice came on the radio … right into our home. He said, “We have nothing to fear but fear itself.” He said our country would make it. We would rise above the present hard times and come out stronger than ever. Those words lifted everybody; I felt them, and I was but a boy. Words have great power for good.
 Sherman, C. E. (2006). Cecil Sherman Formations Commentary, Vol 2: Psalms - Malachi. (p. 64). Macon, GA: Smyth & Helwys Pub.