מֵקִים֙ דְּבַ֣ר עַבְדּ֔וֹ וַעֲצַ֥ת מַלְאָכָ֖יו יַשְׁלִ֑ים הָאֹמֵ֨ר לִירוּשָׁלִַ֜ם תּוּשָׁ֗ב וּלְעָרֵ֤י יְהוּדָה֙ תִּבָּנֶ֔ינָה וְחָרְבוֹתֶ֖יהָ אֲקוֹמֵֽם׃
是我使他僕人的話得以堅立，使他眾使者的謀略得以成就；是我論到耶路撒冷說：«必有人居住»；論到猶大的各城說：«必被重建，其中荒廢之處，我必使它們重新興起。»
Ibn Ezra
His servant. The prophet himself.44I. E. here neglects the rule of the parallelism, which he repeatedly recommends; for that rule demands that עברו and מלאכיו should have the same meaning) and since the latter is a plural, signifying his messengers, עבדו is likewise to be taken in a collective sense, and referred not only to the one prophet who is here speaking, but to all prophets. The word of his servant, that Jerusalem shall be inhabited.
Rashi
and the counsel of His messengers One angel said to Jacob (Gen. 32:27), “Israel shall be your name,” and I fulfilled his words. Here too, I will fulfill the counsel of My prophets who say concerning Jerusalem, “It shall be settled.”