In the first three verses people are plotting evil against God and God's response in v.4 is rather surprising. He laughs. I guess it is a bit like the parent who laughs when their four year old stamps their foot and says, I'm leaving home! The parent knows a child hasn't the resources or knowledge
Yesterday I was at the Dare Conference in Melbourne. Heard some good stuff. Like the story of a missionary in the Philippines who had been witnessing to a guy called Richard. He didn't think it had been going that well because Richard didn't speak much English and the missionary didn't speak much of his language.