But sin, taking occasion by the commandment, wrought in me all manner of concupiscence. For without the law sin was dead.
Paul wrote that sin, taking opportunity by the commandment, produced in him all manner of evil desire. Evil desire here refers to coveting. While the Law forbids all kinds of evil coveting, man’s corrupt nature is inflamed with all the more to do it. Apart from the Law, sin is dead, relatively speaking. When the Law comes and says “don’t”, the flesh wakes up and goes on a rampage, excessively doing whatever is forbidden.