3:1-6 The first words of this chapter seem an answer to the scoffers of those days. Here is a prophecy of the appearing of John the Baptist. He is Christ's harbinger. He shall prepare the way before him, by calling men to repentance. The Messiah had been long called, He that should come, and now shortly he will come. He is the Messenger of the covenant. Those who seek Jesus, shall find pleasure in him, often when not looked for. The Lord Jesus, prepares the sinner's heart to be his temple, by the ministry of his word and the convictions of his Spirit, and he enters it as the Messenger of peace and consolation. No hypocrite or formalist can endure his doctrine, or stand before his tribunal. Christ came to distinguish men, to separate between the precious and the vile. He shall sit as a Refiner. Christ, by his gospel, shall purify and reform his church, and by his Spirit working with it, shall regenerate and cleanse souls. He will take away the dross found in them. He will separate their corruptions, which render their faculties worthless and useless. The believer needs not fear the fiery trial of afflictions and temptations, by which the Saviour refines his gold. He will take care it is not more intense or longer than is needful for his good; and this trial will end far otherwise than that of the wicked. Christ will, by interceding for them, make them accepted. Where no fear of God is, no good is to be expected. Evil pursues sinners. God is unchangeable. And though the sentence against evil works be not executed speedily, yet it will be executed; the Lord is as much an enemy to sin as ever. We may all apply this to ourselves. Because we have to do with a God that changes not, therefore it is that we are not consumed; because his compassions fail not.

3. sit—The purifier sits before the crucible, fixing his eye on the metal, and taking care that the fire be not too hot, and keeping the metal in, only until he knows the dross to be completely removed by his seeing his own image reflected (Ro 8:29) in the glowing mass. So the Lord in the case of His elect (Job 23:10; Ps 66:10; Pr 17:3; Isa 48:10; Heb 12:10; 1Pe 1:7). He will sit down to the work, not perfunctorily, but with patient love and unflinching justice. The Angel of the Covenant, as in leading His people out of Egypt by the pillar of cloud and fire, has an aspect of terror to His foes, of love to His friends. The same separating process goes on in the world as in each Christian. When the godly are completely separated from the ungodly, the world will end. When the dross is taken from the gold of the Christian, he will be for ever delivered from the furnace of trial. The purer the gold, the hotter the fire now; the whiter the garment, the harder the washing [Moore].

purify … sons of Levi—of the sins specified above. The very Levites, the ministers of God, then needed cleansing, so universal was the depravity.

that they may offer … in righteousness—as originally (Mal 2:6), not as latterly (Mal 1:7-14). So believers, the spiritual priesthood (1Pe 2:5).