Malachi 3:2-3

2 ‘But when he comes, he will be like a hot fire that makes metal pure. He will be like strong soap that makes clothes completely clean. Nobody will be able to stand in front of him when he appears. On that day, nobody will remain the same. 3 He will work like a man who uses a hot fire to make gold and silver pure. He will make the Levites clean and pure. He will remove their dirt. Then they can offer proper sacrifices to the Lord.