en_tn_condensed/lam/04/21.md

Rejoice and be glad

"Rejoice" and "be glad" mean basically the same thing and emphasize the intensity of gladness. The writer uses these words to mock the people. He knew that the people of Edom would be glad that Jerusalem is being destroyed. Alternate translation: "Be very glad" (See: rc://en/ta/man/jit/figs-doublet and rc://en/ta/man/jit/figs-irony)

daughter of Edom

The people of the land of Edom are spoken of as if they were a woman. They were Israel's enemy. (See: rc://en/ta/man/jit/figs-personification)

But to you also the cup will be passed

The cup is a metonym for the wine in it. The wine is a metaphor for punishment. Alternate translation: "But Yahweh will also punish you" (See: rc://en/ta/man/jit/figs-metaphor and rc://en/ta/man/jit/figs-metonymy)