The idea that man's law exists or is even needed, implies that there aren't already laws governing all that exists, so we have to make new laws to fill in these gaps.
Considering we don't know everything, it's an arrogant claim we make here. The other approach, and a more humble one too, is to seek to discover the laws already in place that covers all relationships. In other words the rules defining relations between all things (matter) and the rules defining relations between all beings (with all various degrees of independent awareness).
We might call them spiritual laws, divine laws, moral laws, natural laws, physical laws, Sharia law, common law, commerical law etc. but these are just arbitrary classifications of law.
The simple test to figure out if a "law" is a law, is whether it can be applied consistently in the context it is said to be applicable. If it can't, it's something like an opinion but not a law.