malachi 3:5 And I will come near to you to judgment; and I will be a swift witness against the sorcerers, and against the adulterers, and against false swearers, and against those that oppress the hireling in his wages, the widow, and the fatherless, and that turn aside the stranger from his right, and fear not me, saith the LORD of hosts. - Free Bible Online

      5. I . . . come near . . . to judgment--I whom ye challenged, saying, "Where is the God of judgment?" (Mal 2:17). I whom ye think far off, and to be slow in judgment, am "near," and will come as a "swift witness"; not only a judge, but also an eye-witness against sorcerers; for Mine eyes see every sin, though ye think I take no heed. Earthly judges need witnesses to enable them to decide aright: I alone need none (Ps 10:11; 73:11; 94:7, &c.).
      sorcerers--a sin into which the Jews were led in connection with their foreign idolatrous wives. The Jews of Christ's time also practised sorcery (Ac 8:9; 13:6; Ga 5:20; JOSEPHUS [Antiquities, 20.6; Wars of the Jews, 2.12.23]). It shall be a characteristic of the last Antichristian confederacy, about to be consumed by the brightness of Christ's Coming (Mt 24:24; 2Th 2:9; Re 13:13, 14; 16:13, 14; also Re 9:21; 18:23; 21:8; 22:15). Romanism has practised it; an order of exorcists exists in that Church.
      adulterers-- (Mal 2:15, 16).
      fear not me--the source of all sins.

JFB.