The Pulpit Commentary
4. The final separation of the evil and the good at the day of judgment.

Burn as an oven (a furnace). Fire is often spoken of in connection with the day of judgment and the advent of the Judge. It is a symbol of the holiness of God, which consumes all impurity, and also represents the punishment inflicted on the ungodly (Psa_1:1-6 :8; Isa_10:17; Isa_66:15, Isa_66:16; Dan_7:9, Dan_7:10; Joe_2:30; 1Co_3:13; 2Pe_3:7, etc.). The LXX. adds, "and it shall burn them." Stubble (see note on Oba_1:18); or, perhaps, chaff, as Mat_3:11, Mat_3:12. Root nor branch The ungodly are regarded as a tree which is given up to be burned so that nothing of it is left. The same metaphor is used by John the Baptist (Mat_3:10; comp. Amo_2:9). The Hebrew text includes this chapter in Mat_3:1-17.

The Pulpit Commentary
The Sun of Righteousness. The sun which is righteousness, in whose wings, that is, rays, are healing and salvation. This Divine righteousness shall beam upon them that fear the Name of God, flooding them with joy and light, healing all wounds, tee moving all miseries, making them incalculably blessed. The Fathers generally apply the title of "Sun of Righteousness" to Christ, who is the Source of all justification and enlightenment and happiness, and who is called (Jer_23:6), "The Lord our Righteousness." Grow up; rather, gambol; σκιρτήσετε; salietis (Vulgate). "Ye shall leap!" comp. Jeremiah h 11). The word is used of a horse galloping (Habbakuk Jer_1:8). The happiness of the righteous is illustrated by a homely image drawn from pastoral pursuits. They had been, as it were, hidden in the time of affliction and temptation; they shall go forth boldly now, free and exulting, like calves driven from the stall to pasture (comp. Psa_114:4, Psa_114:6; So Psa_2:8, 17).

The Pulpit Commentary
Ye shall tread down the wicked (comp. Mic_4:13). They who were once oppressed and overborne by the powers of wickedness shall now rise superior to all hindrances, and themselves tread down the wicked as the ashes under their feet, to which the fire of judgment shall reduce them. In the day that I shall do this; rather, as in Mal_3:17, in the day which I am preparing.

The Pulpit Commentary
§ 5. Concluding admonition to remember the Law, lest they should be liable to the curse. In order to avert this, the Lord, before his coming, would send Elijah to promote a change of heart in the nation.

If the people would meet the judgment with confidence and secure for themselves the promised blessings, they must remember and obey the Law of Moses. Thus the last of the prophets set his seal to the Pentateuch, on obedience to which depended, as of old (see Lev_26:1-46.; Deu_28:1-68.), so now, the most abundant blessings. My servant. Moses was only the agent and interpreter of God. The origin and authority of the Law were Divine. Horeb. The mention of the mountain would remind the people of the awful wonders that accompanied the promulgation of the Law (Exo_19:16, etc.; Deu_4:10-15) For all Israel Not merely for the people who heard the Law given, but for the nation unto all time. Nor could they be true Israelites unless they observed the terms of the covenant then made. With the (even) statutes and judgments. These terms, which explain the word "Law," include all the enactments, legal, moral, ceremonial. Malachi might well remind the people of their duty, and thus support Nehemiah in his struggle to win them to obedience (see Neh_9:38; Neh_10:29). The LXX. places this verse at the end of the chapter, probably because the original conclusion (verse 6) was thought too harsh to be left as the close of the Old Testament. The Jews had a feeling that books in the Bible should end with the name Jehovah. In the case of Isaiah and Ecclesiastes, they repeated, after the last verse, the last but one.

The Pulpit Commentary
Elijah the prophet. This is not the same personage as the "messenger" in Mal_3:1; for the latter comes before the first advent of the Lord, the former appears before the day of judgment; one comes to prepare the way of the Lord, and is followed immediately by Messiah's coming to his temple; the other is sent to convert the chosen people, lest the land be smitten with a curse. There seems to be no valid reason for not holding the literal sense of the words, and seeing in them a promise that Elijah the prophet, who was taken alive from the earth, shall at the last day coma again to carry out God's wise purposes. That this was the view adopted by the Jews in all ages we see by the version of the LXX; who have here, "Elijah the Tishbite;" by the allusion in Ecclesiasticus 48:10; and by the question of our Lard's disciples in Mat_17:10, "Why then say the scribes that Elias must first come." Christ himself confirms this opinion by answering, "Elias truly shall first come, and restore all things." lie cannot be referring here to John the Baptist, because he uses the future tense; and when he goes on to say that "Elias is come already," he is referring to what was past, and he himself explains that he means John, who was announced to come in the spirit and power of Elias (Luk_1:17), but of whom it could not be said that he "restored all things." The same opinion is found in the Revelation (Rev_11:3, Rev_11:6), where one of the witnesses is very commonly supposed to be Elijah. It is argued by Keil, Reinke, and others, that, as the promise of King David in such passages as Jer_30:9; Eze_34:23; Eze_37:24; Hos_3:5, etc; cannot imply the resurrection of David and his return to earth, so we cannot think of an actual reappearance of Elijah himself, but only of the coming of some prophet with his spirit and power. But, as Knabenbauer points out, for the attribution of the name David to Messiah, long and careful preparation had been made; e.g. by his being called "the rod of Jesse," the occupant of David's throne, etc.; and all who heard the expression would at once understand the symbolical application, especially as David was known to have died and been buried. But when they found Malachi speaking of the reappearance of "Elijah the prophet," who, as they were well aware, had never died, of whose connection with the coming Messenger they had never heard, they could not avoid the conclusion to which they came, viz. that before the great day of judgment Elias should again visit the earth in person. This prophecy concerns the very last days, and intimates that before the final consummation, when iniquity shall abound, God will send this great and faithful preacher of repentance, whose mission shall have such effects that the purpose of God for the salvation of Israel shall be accomplished. We may therefore assume that in the gospel the appellation "Elias" stands both for John and for Elijah himself; for the messenger who prepared the way for Christ's first advent, and for the prophet who was to convert the Israelites before the judgment day; for him who came in spirit and power, and him who shall come in bodily presence. The great and dreadful day. The day of final judgment. No other crisis could be named in such terms (see Joe_2:31, whence the words are taken).

The Pulpit Commentary
He shall turn, etc.; i.e; taking the preposition, rendered "to," in the sense of "with," he shall convert one and all, fathers and children, young and old, unto the Lord. Or, in agreement with the versions, he shall bring back the Jews then living to the faith of their ancestors, who rejoiced to see the day of Christ (Joh_8:56); and then the patriarchs, who for their unbelief had disowned them, shall recognize them as true Israelites, true children of Abraham. Others explain—He shall unite the Jews who are our fathers in the faith to us Christians who are their children (see Luk_1:17, where the angel Gabriel quotes part of the passage, and applies it to John the Baptist). The heart. Here not the seat of the intellectual powers, but of love and confidence, which lead to union and concord. Lest I come and smite the earth with a curse; or, smite the land with the ban. This is an allusion to the ban threatened in the Law, which involved extermination (see Le 27:29; Deu_13:16, Deu_13:17; Deu_20:16, Deu_20:17). So Elijah shall come and preach repentance, as the Baptist did at Christ's first coming; and unless the Jews listen to him and turn to Christ, they shall be destroyed, shall share in that eternal anathema which shall fall on the ungodly at the day of judgment.