Why would rulers benefit if they claimed to be chosen by the gods?

Rulers would benefit if they claimed to be chosen by a god or gods because it could potentially give them religious legitimacy with their people. In many theocracies leaders argue that they were chosen by god to lead a country and are therefore ordained to lead by a higher power. This then entitles them to protection from the people to demand too much or to attempt to impact the policies of the government or the leader for fear of interfering with god or the gods decision.