his passage is a little strange. David spends most of this psalm describing the ways of wicked men. Why? Because, he was again in the spirit of imprecation. He wondered honestly why God was not more punctual in His execution of justice against evil men. By the way, even though David doesn't find the answer in this Psalm, we know why. II Peter 3:7-9 tells us that God's patience (and the delay in rectification that His patience produces) reflects His desire to see evil men repent. But, II Peter 3:10 reminds us that God will not wait forever. He will bring justice in His time. Romans 9:22 & 23 also give us a peek into a deeper reason behind what may appear to us at times to be a strange divine tolerance for overt wickedness. God has a program of revealing Himself and of delivering His children. And, His program allows for and even utilizes (shall we even say, exploits) His enemies. David didn't see these things though... at least not in Psalm 10.
So, he describes the evil of evil men. The thing that seems to bother David the most is that evil men see God's longsuffering inaction and interpret it as disinterest or ignorance. So, David imprecates the wicked around him by asking God to defend the humble; to rise up and act. David was confident that the perishing of iniquitous men and the blessing of the humble was indeed inevitable and impending.