John Calvin Commentary Deuteronomy 16:18

"Judges and officers shalt thou make thee in all thy gates, which Jehovah thy God giveth thee, according to thy tribes; and they shall judge the people with righteous judgment." — Deuteronomy 16:18 (ASV)

Judges and officers you shall make. I have placed this passage among the Supplements of the Fifth Commandment, because if it pleases God that judges should be appointed for ruling the people, it follows that their laws and edicts should be obeyed; and thus the parental authority also extends to them.

But, so that the people may submit themselves more readily to judges, God reminds them that the human race could not otherwise be preserved. Public utility, therefore, makes the authority of magistrates pleasant and agreeable, though it would otherwise be hateful.

But, although it is not conceded to all to elect their judges, because God honored His chosen people with this prerogative, still He here recommends in general a regular government, since He signifies that human society cannot hold together unless the lawful rulers have authority to execute justice. Whether, then, magistrates are appointed by the votes of the people, or imposed in any other way, let us learn that they are the necessary ministers of God, to confine all men under the yoke of the laws.

The latter passage, which I have annexed from Deuteronomy 7, refers to the same thing, namely, that even in war discipline is necessary, lest all things be thrown into confusion. Now, if it pleases God that certain superior officers should have the command, it follows that they must be obeyed, for it would be ridiculous to appoint governors if it were lawful to despise them with impunity. When, therefore, God sets military commanders over the people, He enforces the duty of humble submission.