Nahum 1:2

God [is] jealous, and the LORD revengeth; the LORD revengeth, and [is] furious; the LORD will take vengeance on his adversaries, and he reserveth [wrath] for his enemies.

Ver. 2. God is jealous] See Trapp on " Zec 1:14 "

And the Lord revengeth, the Lord revengeth] As he is Pater miserationum to his people, a father of mercies, and God of consolation; so to his and their enemies he is a most sure and severe revenger: Deus ultionum, as David calleth him, Psalms 94:1. A God of recompenses, as Jeremiah, Jeremiah 51:56. And when he comes against a people, he usually takes them to do when they are at the strongest and most confident; as Nineveh now was, in the days of proud Sennacherib.

And is furious] Heb. And is master of hot wrath; he is all on a light fire, as it were, with fierce indignation against the enemies of his Church; yet not so, but that he is master of his anger too; and doth nothing in it but what is just and equal. Here the vials of his wrath are said to be golden vials, Revelation 15:7, his anger is holy, his fire is pure, and without smoke. And this is further declared in the following words.

The Lord will take vengeance on his adversaries] Such as seek to thrust him beside his throne, that oppose his worship, contemn his word, persecute his people, send proud messages after him, saying, "We will not have this man to reign over us," "Bring hither those mine enemies," saith he, "and slay them before me," Luke 19:27. As for such as sin of infirmity and return to him by repentance, they shall not find him furious, but gracious.

And he reserveth wrath for his enemies] Their preservation for a time is but a reservation to that wrath to come. As he precipitateth not his anger, but defers the execution of it, giving men space to repent, as he did Jezebel, Revelation 2:20, so they shall find that his forbearance is no quittance; and that

Poena venit gravior, quo mage tarda venit

The penalty comes more heavily which comes with great slowness.