Can You Explain The Ecclesiastes Chapter 7 Verse 9?

Do not be quickly provoked in your spirit,
      for anger resides in the lap of fools.  Basically your anger is quick and ill tempered and that's an acquiring of Satan. He provokes you to do things that are not normal or things that are ungodly like curse or flip out and say things that don't need to be said. Its all spiritual, period. Saying that, that means that you are dealing with the demonic. The spirit of Anger, jealousy, envy and so forth come from the same tree. Just think of different things we as humans do that are stupid or silly and most have a demonic spirit behind them. Its all the Word of God, check it out.

It means you should not get angry because anger is of the devil

It say "Do not hasten in your spirit to be angry, For anger rests in the bosom of fools."  We should not get angry so quickly when someone does you wrong, for it will not give you the satisfied result.  Anger can cause you both to fight which is not the required result. Stay calm and work out the problems, for it say's the anger rest in those who likes to fight with others when there is a solution to the problem.

Ecclesiastes 7:9 Do not be quickly provoked in your spirit, for anger resides in the lap of fools. Patience is needed to see our resolutions and enterprises through to the end. How often we embark on something with pride in our ability to carry it through but abandon it because of a few discouragements! Then we may become angry and lash out at other people as an excuse for our own incompetence.