The word command carries the idea of authority. The most basic meaning of the word is “to direct with authority.” A command does not just give guidance that one may accept or reject; a command implies that the one giving it has the authority to require obedience and the intention of doing so. This is true of the commands of God. As the Sovereign God of the universe, He has the authority to require obedience and He does insist that we obey Him.
Jerry Bridges