Philo Judaeus De Agricultura 41

These, then, are the occupations of shepherds who prefer those things which are useful, though mixed with unpleasantness, to those which are pleasant but pernicious. Thus, at all events, the occupation of a shepherd has come to be considered a respectable and profitable employment, so that the race of poets has been accustomed to call kings the shepherds of the people; but the law giver gives this title to the wise, who are the only real kings, for he represents them as rulers of all men of irrational passions, as of a flock of sheep.