Nahum begins to describe Yahweh coming to judge his enemies and to save his people. The vision is full of metaphorical language and uses different kinds of parallelism. (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-parallelism]])
This is the name of God that he revealed to his people in the Old Testament. See the translationWord page about Yahweh concerning how to translate this.