Zephaniah writes in poetry from this verse until the end of the book. Parallelism is common in Hebrew poetry. (See: [[rc://en/ta/man/jit/writing-poetry]] and [[rc://en/ta/man/jit/figs-parallelism]])
The words "everything" and "will cut off man" are deliberate exaggerations by Yahweh to express his anger at the people's sin. Yahweh will destroy neither sinners who repent nor all living things. (See: [[rc://en/ta/man/jit/figs-hyperbole]])
Yahweh speaks of himself by name to express the certainty of what he is declaring. Alternate translation: "this is what Yahweh has declared" or "this is what I, Yahweh, have declared" (See: [[rc://en/ta/man/jit/figs-123person]])