Pro 20:19 He that goeth about as a talebearer revealeth secrets: therefore meddle not with him that flattereth with his lips.
Pro 20:20 Whoso curseth his father or his mother, his lamp shall be put out in obscure darkness.
Pro 20:21 An inheritance may be gotten hastily at the beginning; but the end thereof shall not be blessed.
Pro 20:22 Say not thou, I will recompense evil; but wait on the LORD, and he shall save thee.
Pro 20:23 Divers weights are an abomination unto the LORD; and a false balance is not good.
Pro 20:24 Man's goings are of the LORD; how can a man then understand his own way?
19 tells us not to hang out with gossipers. Of course we know that anyway, but we still do it. How else would we get our gossip? And yet we’re probably surprised when he or she shares our secrets as well. It is good to remember that someone who can’t keep someone else’s secret can’t keep ours.
Verse 22 is against revenge. Vengeance is the Lord’s, not ours. We must do what is necessary to establish society but not go so far as to take revenge. We are to wait on God for that.