I find the scripture itself beautiful. To me it says a couple of things.
1. It is okay to enjoy the rewards of hard work. God approves of your rejoicing over things you have accomplished in life.
2. The hard work a person does should be rewarded to him himself and not be passed on to someone lording it over him, be it government, business or religion asking for the tribute. No, instead, each person's work, reward and thankfulness is between himself and God.
It is interesting to me that the Watchtower society immediately looks on this as having some future application as opposed to talking about how it applies to our life now. That clearly matches their agenda, but I wonder if it matches the agenda of God and Solomon who recorded the words.
Joel