God's judgment on the wicked,
Malachi 4:1 For, behold, the day cometh, it burneth as a furnace; and all the proud, and all that work wickedness, shall be stubble: and the day that cometh shall burn them up, saith the LORD of hosts, that it shall leave them neither root nor branch.
and his blessing on the good.
Malachi 4:2 But unto you that fear my name shall the sun of righteousness arise with healing in his wings; and ye shall go forth, and gambol as calves of the stall. 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 do make, saith the LORD of hosts.
He exhorteth to the study of the Law,
Malachi 4:4 Remember ye the law of Moses my servant, which I commanded unto him in Horeb for all Israel, even statutes and judgments.
and telleth of Elijah's coming and office.
Malachi 4:5 Behold, I will send you Elijah the prophet before the great and terrible day of the LORD come. Malachi 4:6 And he shall turn the heart of the fathers to the children, and the heart of the children to their fathers; lest I come and smite the earth with a curse.