The city of Zion, which is also called Jerusalem, here represents the people of Zion. Alternate translation: "Yahweh will comfort the people of Zion" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Here "waste places" represents the people who live in those desolate areas. Alternate translation: "he will comfort the people who live in all her waste places" (See: [[rc://en/ta/man/translate/figs-metonymy]])
These phrases mean that God will make the empty places in Israel beautiful. In prophecy, events that will happen in the future are often described as being in the past. This emphasizes that they will certainly happen. Alternate translation: "he will make her wilderness like Eden and her desert plains ... like the garden of Yahweh (See: [[rc://en/ta/man/translate/figs-parallelism]] and [[rc://en/ta/man/translate/figs-pastforfuture]])
Joy and gladness mean the same thing. Being found there represents being there. Alternate translation: "there will be joy and gladness in Zion again" (See: [[rc://en/ta/man/translate/figs-doublet]] and [[rc://en/ta/man/translate/figs-activepassive]])