The burden - Jerome: “The word משׂא mas's'â', ‘burden’ is never placed in the title, except when the vision is heavy and full of burden and toil.”
Of Nineveh - The prophecy of Nahum again is very stern and awful. Nineveh, after having “repented at the preaching of Jonah,” again fell back into the sins whereof it had repented, and added this, that, being employed by God to chasten Israel, it set itself, not to inflict the measure of God’s displeasure, but to uproot the chosen people, in whom was promised the birth of Christ . It was then an antichrist, and a type of him yet to come. Jonah’s mission was a call to repentance, a type and forerunner of all God’s messages to the world, while the day of grace and the world’s probation lasts. Nahum, “the full of exceeding comfort,” as his name means, or “the comforter” is sent to John 16:6, John 16:8. “reprove the world of judgment.” He is sent, prominently, to pronounce on Nineveh its doom when its day of grace should be over, and in it, on the world, when it and “all the works therein shall be burned up” 2 Peter 3:10.
With few words he directly comforts the people of God Nahum 1:15; elsewhere the comfort even to her is indirect, in the destruction of her oppressor. Besides this, there is nothing of mercy or call to repentance, or sorrow for their desolation (as in Jeremiah 3:12; Jeremiah 8:18, Jeremiah 8:21), but rather the pouring out of the vials of the wrath of God upon her and on the evil world, which resists to the end all God’s calls and persecutes His people. The Book of Jonah proclaims God, “a gracious God and merciful, slow to anger and of great kindness, who repents Him of the evil.” Nahum speaks of the same attributes, yet closes with, “and will not at all acquit the wicked.” : “The Merciful Himself, who is by Nature Merciful, the Holy Spirit, seemeth, speaking in the prophet, to laugh at their calamity.” All is desolation, and death. The aggression against God is retorted upon the aggressor; one reeling strife for life or death; then the silence of the graveyard. And so, in its further meaning , “the prophecy belongs to the close of the world and the comfort of the saints therein, so that whatsoever they see in the world, they may hold cheap, as passing away and perishing and prepare themselves for the Day of Judgment, when the Lord shall he the Avenger of the true Assyrian.”
So our Lord sets forth the end of the world as the comfort of the elect. “When these things begin to come to pass, then look up and lift up your heads, for your redemption draweth nigh” Luke 21:28. This is the highest fulfillment of the prophecy, for “then will the wrath of God against the wicked be fully seen, who now patiently waiteth for them for mercy.”
The book of the vision of Nahum the Elkoshite - o “He first defines the object of the prophecy, whereto it looks; then states who spake it and whence it was;” the human instrument which God employed. The fuller title, “The book of the vision of Nahum” (which stands alone) probably expresses that it was not, like most prophecies, first delivered orally, and then collected by the prophet, but was always (as it is so remarkably) one whole. “The weight and pressure of this ‘burden.’ may be felt from the very commencement of the book.”