The Hebrew word translated ‘sport’ means ‘laughter’. It comes from a root word meaning ‘to laugh’, ‘to play’, or ‘to mock’, and seems to be used of either derisive laughter, or smug satisfied laughter.
Here is a Christian let us say, a child of God, who slips into that lifestyle. His enjoyment is getting what he wants, getting satisfaction in his urges and desires, that is what makes him laugh, that is what pleases him. Why, it is obvious to other believers, he is a person out of control, he is a person whose old nature has taken over and is ruling. You see him running about here and there, not in order to hunt for food, as they may well have had to do, but just for sport, just to triumph. Sadly, that is the contrast which the picture is putting across. The believer can let the old nature rise up again and rule. ‘I have set my heart on having this or that in my home. I have set my heart on some acquisition, and I plan it, and now my plan is coming to fruition. It may not be particularly wicked, but it may be something you do not need; you may be pampering yourself.