Malachi 3:2-3

And who can endure the day of his coming? And who is the one who can stand when he appears? For he is like a refiner’s fire, like launderers’ alkali. He will sit as a refiner and purifier of silver; he will purify the children of Levi, and he will refine them like gold and like silver, and they will present to Yahweh offerings in righteousness.