1 Samuel 10:17

31. Mizpah, as I said, is interpreted as "watchtower." In the ordination of the king, the people are called to Mizpah, because those who come together to ordain a pastor of holy Church are taught to attend to his spiritual qualities, not his carnal ones. To watch, indeed, is to recognize the preacher to be ordained through the standard of sacred Scripture. For sacred Scripture is the mirror of the elect. A pastor is known as if through a mirror, when he is shown by his conduct to be such as is proclaimed in sacred eloquence. Rightly, therefore, Samuel convokes the people at Mizpah, so that the election of a good bishop may not rest on human judgment, but on divine: since there is elected not such a one as can be determined by the will of men, but such as is declared in sacred eloquence. Because this is a gift of God, it is necessary that the people, who are known to expect such great things from God, be purged of their guilt through the satisfaction of penance. Moreover, the very recognition of sin is a preparation for the divine gift, because often when we believe ourselves unworthy of the divine gift, we merit it through humility. Hence Samuel also strives to turn those who had gathered to receive the king first to the consideration of their sins.