World Wide Study Bible
a Bible passage
The Prophet says, that Christ would sit to purify the sons of Levi; for though they were the flower, as it were, and the purity of the Church, they had yet contracted some contagion from the corruption which prevailed. Such then was the contagion, that not only the common people became corrupt, but even the Levites themselves, who ought to have been guides to others, and who were to be in the Church as it were the pattern of holiness. God however promises that such would be the purifying which Christ would effect, and so regulated, that it would consume the whole people, and yet purify the elect, and purify them like silver, that they may be saved. He tells us afterwards that the Levites themselves would need a trial to cleanse them; for they themselves would not be without filth, because they had mixed with a perverse people, who had wholly departed from the law, and from the fear and the worship of God.