Numbers 16:8

8.Hear, I pray you, ye sons of Levi. He addresses the whole body, and yet it is said that his discourse was directed to Korah alone, and this was because he had corrupted others of the Levites, and therefore is first summoned to God’s tribunal, so that the whole party might be at the same time included. He was able to expostulate with the Levites at once, because their residence was close to the sanctuary.

He accuses them of ingratitude, because they were not satisfied with the honor with which God had already dignified them, but also sought the high-priesthood. In this they betrayed their despisal of His grace; for, if they had rightly valued the gifts of God, each of them would have quietly contented himself with his lot; especially since, in proportion as a person has been liberally dealt with, his ingratitude is more intolerable, if he aspires to anything higher. We are taught, therefore, that the higher the degree may be to which we have been elevated by God’s goodness, the greater is the punishment which our crime deserves, if our ambition still incites us to overleap the bounds of our calling. Nevertheless, such is the perversity of almost all men, that as soon as a person has attained some intermediate position, he uplifts, as it were, the standard of pride (91) and prescribes to himself no limit, until he shall have reached above the clouds. In a word, few are found who do not grow insolent in places of honor. Wherefore we ought to be all the more attentive to this admonition of Moses, that those are most ungrateful to God who despise their lot, which is already honorable, and aim at something higher.