Exodus 18:17-20

"And Moses' father-in-law said unto him, The thing that thou doest is not good. Thou wilt wear away, both thou, and this people that is with thee: for the thing is too heavy for thee; thou art not able to perform it thyself alone. Hearken now unto my voice, I will give thee counsel, and God be with thee; be thou for the people to Godward, and bring thou the causes unto God: and thou shalt teach them the statutes and the laws, and shalt show them the way wherein they must walk, and the work that they must do."

The advice that Jethro gave did not in any manner encroach upon Moses' authority nor erode his position as Leader and Lawgiver for the people, but it merely opened up some ways by which Moses would be able to conserve his energies and strength for more important matters, while, at the same time delegating numerous and less important things to others. In the next paragraph, Jethro suggested some qualifications for such men as Jethro would recommend for appointment to the delegated places of authority Jethro had suggested.