Malachi 3:5

5 And I shall come to you in doom, and I shall be a swift witness to mis-doers, either enchanters of devil's craft, and to adulterers, and to forsworn men, and that falsely challenge the hire of an hired man, and widows, and fatherless children, and oppress a pilgrim, and dreaded not me, saith the Lord of hosts. (And I shall come to you in judgement, and I shall be a swift witness against all evil-doers, that is, enchanters of the devil's craft, and adulterers, and perjurers, and those who cheat hired men out of their wages, and do wrong to widows, and fatherless, or motherless, children, and foreigners, yea, those who do not fear me/yea, those who do not revere, or respect, me, saith the Lord of hosts.)

Malachi 3:5 Meaning and Commentary

Malachi 3:5

And I will come near to you to judgment
And so will manifestly appear to be the God of judgment they asked after, ( Malachi 2:17 ) this is not to be understood of Christ's coming to judgment at the last day, but of his coming to judge and punish the wicked Jews at the time of Jerusalem's destruction; for the same is here meant, who is spoken of in the third person before, and who will not be afar off; there will be no need to inquire after him, when he will come he will be near enough, and too near for them: and I will be a swift witness against the sorcerers;
not only a judge, but a witness; so that there will be no delay of judgment, or protracting or evading it, for want of witnesses of facts alleged; for the Judge himself, who is Christ, will be witness of them, he being the omniscient God, before whom all things are manifest. The Targum is,

``my Word shall be among you for a swift witness.''

Mention is made of "sorcerers", because there were many that used the magic art, enchantments, and sorceries, in the age of Christ and his apostles, and before the destruction of Jerusalem, even many of their doctors and members of the sanhedrim; (See Gill on Isaiah 8:19): and against the adulterers;
with whom that age also abounded; hence our Lord calls it an adulterous generation, ( Matthew 12:39 ) ( John 8:3-9 ) ( Romans 2:22 ) : and against false swearers;
who were guilty of perjury, and of vain oaths; who swore by the creatures, and not by the Lord, and to things not true; see ( Matthew 5:33-37 ) : and against those that oppress the hireling in [his] wages, the
widow, and the fatherless;
defrauding of servants of their wages, devouring widows' houses, and distressing the fatherless, were sins the Jews were addicted to in those times, as appears from ( James 1:27 ) ( 5:4 ) who wrote to the twelve tribes; and from what our Lord charges them with, ( Matthew 23:14 ) : and that turn aside the stranger [from his right];
and so Kimchi supplies it,

``that turn aside the judgment of the stranger;''

that do not do him justice in civil things; yea, persecuted those that became proselytes to the Christian religion: and fear not me, saith the Lord of hosts;
which was the root and cause of all their sins; irreverence of Christ, disbelief of him, and contempt of his Gospel.

Malachi 3:5 In-Context

3 and he shall sit welling together and cleansing silver, and he shall purge the sons of Levi; and he shall purge them as gold and as silver, and they shall be offering to the Lord sacrifices in rightwiseness. (and he shall sit welling together and cleansing, or purging and refining, silver, and he shall purge the Levites; yea, he shall refine them like gold and silver, and then they shall offer to the Lord sacrifices in righteousness.)

4 And the sacrifice of Judah and of Jerusalem shall please the Lord, as the days of the world, and as old years. (And then the sacrifices, or the offerings, of Judah and of Jerusalem shall please the Lord, like in the days of old, and like in the years long ago.)

5 And I shall come to you in doom, and I shall be a swift witness to mis-doers, either enchanters of devil's craft, and to adulterers, and to forsworn men, and that falsely challenge the hire of an hired man, and widows, and fatherless children, and oppress a pilgrim, and dreaded not me, saith the Lord of hosts. (And I shall come to you in judgement, and I shall be a swift witness against all evil-doers, that is, enchanters of the devil's craft, and adulterers, and perjurers, and those who cheat hired men out of their wages, and do wrong to widows, and fatherless, or motherless, children, and foreigners, yea, those who do not fear me/yea, those who do not revere, or respect, me, saith the Lord of hosts.)

6 Forsooth I am the Lord, and I am not changed; and ye sons of Jacob be not wasted. (Yea, I am the Lord, and I do not change; and so ye sons of Jacob be not completely lost, or separated from me.)

7 Forsooth from the days of your fathers ye went away from my lawful things, and kept not; turn ye again to me, and I shall again turn to you, saith the Lord of hosts. And ye said, In what thing shall we turn again? (Though from the days of your forefathers ye went away from my laws, and did not keep them; return ye to me, and I shall return to you, saith the Lord of hosts. And ye said, How can we return to thee?/Though from the days of your forefathers ye went away from my laws, and did not keep them; turn ye back to me, and I shall turn back to you, saith the Lord of hosts. And ye said, How do we turn back to thee?)