malachi 3:1 Behold, I will send my messenger, and he shall prepare the way before me: and the Lord, whom ye seek, shall suddenly come to his temple, even the messenger of the covenant, whom ye delight in: behold, he shall come, saith the LORD of hosts. - Free Bible Online

      Mal 3:1-18. MESSIAH'S COMING, PRECEDED BY HIS FORERUNNER, TO PUNISH THE GUILTY FOR VARIOUS SINS, AND TO REWARD THOSE WHO FEAR GOD.

      1. Behold--Calling especial attention to the momentous truths which follow. Ye unbelievingly ask, Where is the God of judgment (Mal 2:7)? "Behold," therefore, "I send," &c. Your unbelief will not prevent My keeping My covenant, and bringing to pass in due time that which ye say will never be fulfilled.
      I will send . . . he shall come--The Father sends the Son: the Son comes. Proving the distinctness of personality between the Father and the Son.
      my messenger--John the Baptist; as Mt 3:3; 11:10; Mr 1:2, 3; Lu 1:76; 3:4; 7:26, 27; Joh 1:23, prove. This passage of Malachi evidently rests on that of Isaiah his predecessor (Isa 40:3-5). Perhaps also, as HENGSTENBERG thinks, "messenger" includes the long line of prophets headed by Elijah (whence his name is put in Mal 4:5 as a representative name), and terminating in John, the last and greatest of the prophets (Mt 11:9-11). John as the representative prophet (the forerunner of Messiah the representative God-man) gathered in himself all the scattered lineaments of previous prophecy (hence Christ terms him "much more than a prophet," Lu 7:26), reproducing all its awful and yet inspiriting utterances: his coarse garb, like that of the old prophets, being a visible exhortation to repentance; the wilderness in which he preached symbolizing the lifeless, barren state of the Jews at that time, politically and spiritually; his topics sin, repentance, and salvation, presenting for the last time the condensed epitome of all previous teachings of God by His prophets; so that he is called pre-eminently God's "messenger." Hence the oldest and true reading of Mr 1:2 is, "as it is written in Isaiah the prophet"; the difficulty of which is, How can the prophecy of Malachi be referred to Isaiah? The explanation is: the passage in Malachi rests on that in Isa 40:3, and therefore the original source of the prophecy is referred to in order to mark this dependency and connection.
      the Lord--Ha-Adon in Hebrew. The article marks that it is JEHOVAH (Ex 23:17; 34:23; compare Jos 3:11, 13). Compare Da 9:17, where the Divine Son is meant by "for THE Lord's sake." God the speaker makes "the Lord," the "messenger of the covenant," one with Himself. "I will send . . . before Me," adding, "THE LORD . . . shall . . . come"; so that "the Lord" must be one with the "Me," that is, He must be GOD, "before" whom John was sent. As the divinity of the Son and His oneness with the Father are thus proved, so the distinctness of personality is proved by "I send" and He "shall come," as distinguished from one another. He also comes to the temple as "His temple": marking His divine lordship over it, as contrasted with all creatures, who are but "servants in" it (Hag 2:7; Heb 3:2, 5, 6).
      whom ye seek . . . whom ye delight in--(see on Mal 2:17). At His first coming they "sought" and "delighted in" the hope of a temporal Saviour: not in what He then was. In the case of those whom Malachi in his time addresses, "whom ye seek . . . delight in," is ironical. They unbelievingly asked, When will He come at last? Mal 2:17, "Where is the God of judgment" (Isa 5:19; Am 5:18; 2Pe 3:3, 4)? In the case of the godly, the desire for Messiah was sincere (Lu 2:25, 28). He is called "Angel of God's presence" (Isa 63:9), also Angel of Jehovah. Compare His appearances to Abraham (Ge 18:1, 2, 17, 33), to Jacob (Ge 31:11; 48:15, 16), to Moses in the bush (Ex 3:2-6); He went before Israel as the Shekinah (Ex 14:19), and delivered the law at Sinai (Ac 7:38).
      suddenly--This epithet marks the second coming, rather than the first; the earnest of that unexpected coming (Lu 12:38-46; Re 16:15) to judgment was given in the judicial expulsion of the money-changing profaners from the temple by Messiah (Mt 21:12, 13), where also as here He calls the temple His temple. Also in the destruction of Jerusalem, most unexpected by the Jews, who to the last deceived themselves with the expectation that Messiah would suddenly appear as a temporal Saviour. Compare the use of "suddenly" in Nu 12:4-10, where He appeared in wrath.
      messenger of the covenant--namely, of the ancient covenant with Israel (Isa 63:9) and Abraham, in which the promise to the Gentiles is ultimately included (Ga 4:16, 17). The gospel at the first advent began with Israel, then embraced the Gentile world: so also it shall be at the second advent. All the manifestations of God in the Old Testament, the Shekinah and human appearances, were made in the person of the Divine Son (Ex 23:20, 21; Heb 11:26; 12:26). He was the messenger of the old covenant, as well as of the new.

JFB.