Charles Spurgeon Commentary Malachi 3:4-5

"Then shall the offering of Judah and Jerusalem be pleasant unto Jehovah, as in the days of old, and as in ancient years. 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 the false swearers, and against those that oppress the hireling in his wages, the widow, and the fatherless, and that turn aside the sojourner [from his right], and fear not me, saith Jehovah of hosts." — Malachi 3:4-5 (ASV)

See how hard taskmasters are put, by divine inspiration, with sorcerers, adulterers, and false swearers. They do not think badly of themselves, but the Lord thinks badly of them, and His judgment is always just.