And Moses said unto his father in law, Because the people come unto me to inquire of God: The people come unto me to inquire of God - To know the mind and will of God on the subject of their inquiries. Moses was the mediator between God and the people; and as they believed that all justice and judgment must come from him, therefore they came to Moses to know what God had spoken.
Related Commentaries of Exodus 18:15
Exodus 18:15
15 And Moses said unto his father in law, Because the people come unto me to enquire of God: