Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 2:3-9, 21-23.
Haggai uses an extended metaphor in this chapter related to ritual cleanliness. While the Jews were not unclean by nature as the Gentiles were, their actions made them unclean. (See: [[rc://en/ta/man/jit/figs-metaphor]] and [[rc://en/tw/dict/bible/kt/clean]])