v1: Like Habakkuk and Jeremiah, Zephaniah looks at events leading up to the defeat and exile of Judah. The dominant power is changing from Assyria to Babylon. Josiah is the great reforming king, yet the people's hearts still pursued idolatry.
v2-3: Widespread and severe judgment; see Is 24. The plans of the wicked will come to nothing, and their hopes dashed.
v4-6: Judah and Jerusalem to be destroyed; the reason is clear, idolatry, albeit mixed with true worship; Baal, idolatrous priests, the host of heaven, Molech, yet they still "bow down and swear by the Lord." The reality is that they have rebelled against the Lord God; He is jealous and will tolerate no rivals. In the human heart, a mixture of religions is deemed acceptable, by which we avoid any accusation of fanaticism or fundamentalism, but such alloyed religion is an abomination to God.
The judgment upon the people is also a purging, "I will cut off from this place every remnant..."
Back in 1 Sam 5.1-5, God demonstrated the folly of idolatry, but here, some 500 years later, that message is forgotten; the people now know better!
v7: No more excuses, no more arguments, be silent; like Job, we must lay our hand over our mouth (Job 40.4). Judgment is coming, the Day of the Lord is "near," the day of sacrifice.
v8: Zephaniah addresses the princes, the king's sons; Josiah's children, who do not follow the Lord, nor even their father's example. They are clothed in foreign apparel, indicating that they have sought the help of Gentile nations, and have become subject to them.
v9: They leap over the threshold of the temple to commit idolatry; se 1 Sam 55. They continue in violence and deceit, sins previously condemned by Amos and Micah. God sent prophet after prophet to Israel, and also godly reforming kings to Judah, yet these sins returned persistently; the Lord's command, "repent," means to break with such sins. David kept himself from his iniquity, 2 Sam 22.24.
v10-13: Describing the defeat of Jerusalem; compare Mic 3.11-12; riches and complacency, Deut 28.39; Amos 6.1. The people consider God to be impotent, "The Lord will do nothing, either good of bad." A further reason for the judgment is the demonstration that God is both active and powerful.
It is time for action; elsewhere we read the command to "arise!" to Abraham (Gen 13.17); to Lot (Gen 19.15); to Jacob (Gen 31.13); to Moses (Deut 9.12); to Barak (Judg 5.12); to Gideon (Judg 7.9); to Samuel (1 Sam 16.12); to David (1 Sam 23.4); to Jeroboam's wife (1 Kings 14.12); to Elijah (1 Kings 17.9); Jezebel to Ahab (1 Kings 21.15); to Solomon (1 Chr 22.16,19); to Ezra (Ez 10.4); each time there is a call to urgent action; Joel 1.13-14; 2.15-17.
v14-16: The Day of the Lord is near, as in v7, Amos 5.18. This is a time of fear for many, a time when fortified cities and high towers prove useless.
v17: There is always good reason for God's judgment, because the people have sinned against the great God; these dreadful events described are not simply something awful that happened, but what God appointed.
v18: The riches, accumulated by the people, are useless. The whole land will be devoured, not just parts of Israel (see 2 Kings 10.32).
There is the fire of His jealousy, a fire of purging and judgment. There is a sudden end, for the Lord is acting with urgency and decisiveness; a reminder of previous calls to the people that they act urgently to seek the Lord, which they failed to do.