Yahweh is saying the same thing twice to emphasize that it is only he, Yahweh, who causes the prophesies to be fulfilled. (See: [[rc://en/ta/man/translate/figs-parallelism]])
The abstract nouns "words" and "predictions" can be translated as verbs. Alternate translation: "what his servant declares ... what his messengers announce" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
The phrase "ruins" refers to places that have been destroyed. Yahweh speaks of rebuilding them as if he were raising them up. Alternate translation: "I will rebuild what others have destroyed" (See: [[rc://en/ta/man/translate/figs-metaphor]])