John Calvin Commentary Numbers 16:8

"And Moses said unto Korah, Hear now, ye sons of Levi:" — Numbers 16:8 (ASV)

Hear, I ask you, you sons of Levi. He addresses the whole body, and yet it is said that his discourse was directed to Korah alone, because he had corrupted others of the Levites and was therefore first summoned to God’s tribunal, so that the whole party might be included at the same time. 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 contempt 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 dealt with generously, 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 people, that as soon as a person has attained some intermediate position, he uplifts, as it were, the standard of pride⁹¹ and sets no limit for himself, until he has reached above the clouds. In a word, few are found who do not grow insolent in places of honor.

Therefore, we should 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.

⁹¹ “Comme si Dieu en l’honorant luy avoit dresse une banniere d’orgueil;” as if God by honoring him had raised for him a banner of pride. — Fr..