Imagine a little monkey who sees a banana inside a jar with a narrow opening. He reaches in, grabs the banana (that's the wanting), but now his hand won't come out because it's closed around the fruit. He gets stuck in the trap of his own wanting!
The Bible says that dishonesty (lying, cheating, taking what isn't yours) is just like that. It looks like you're about to win something, but you end up stuck in problems and lies. Honesty is letting go of the banana and pulling your hand out free. Whoever tells the truth is free and doesn't get stuck in confusion!