Albert Barnes Commentary Malachi 4:3

"And ye shall tread down the wicked; for they shall be ashes under the soles of your feet in the day that I make, saith Jehovah of hosts." — Malachi 4:3 (ASV)

And you shall tread down the wicked, for they shall be ashes under the soles of your feet. It shall be a great reversal. He that exalts himself shall be abased, and he that humbles himself shall be exalted – here the wicked often have the pre-eminence. This was the complaint of the murmurers among the Jews; in the morning of the Resurrection (Psalms 49:14), the upright shall have dominion over them.

The wicked, he had said, shall be as stubble, and that day (Psalms 4:1), shall burn them up; here, then, they are as the ashes, the only remnant of the stubble, as the dust under the feet.

The elect shall rejoice that they have, in mercy, escaped such misery. Therefore they shall be kindled inconceivably with the divine love and shall from their inmost heart give thanks to God. And being thus of one mind with God, and seeing all things as He sees, they will rejoice in His judgments, because they are His.

For they cannot have the slightest wish other than the all-perfect Will of God. So Isaiah closes his prophecy (Isaiah 66:24), And they shall go forth, and look upon the carcasses of the men who have transgressed against Me, for their worm shall not die, neither shall their fire be quenched, and they shall be an abhorrence to all flesh. So (Psalms 58:10). The righteous shall rejoice when he sees the vengeance; and another Psalmist (Psalms 107:42), The righteous shall see and rejoice; and all wickedness shall stop her mouth; and Job (Job 22:19). The righteous see and are glad, and the innocent laugh them to scorn.