Isaiah 42:9

הָרִאשֹׁנוֹת הִנֵּה־בָאוּ וַחֲדָשׁוֹת אֲנִי מַגִּיד בְּטֶרֶם תִּצְמַחְנָה אַשְׁמִיע אֶתְכֶם׃

9 The former things: Behold! They came true! And I am declaring new things; before they spring into being, I make them known to you.

הָרִאשֹׁנוֹת הִנֵּה־בָאוּ The former things: Behold! They came true! In 41:22, הָרִאשֹׁנוֹת refers to something like "the recent future." Here it contrasts things that have not yet taken place, and it means things that were once foretold and then happened just as they had been prophesied. The Old Testament is riddled with these fulfilled prophecies. The building of the nation from Abraham and Sarah's son is one of the greatest examples. הָרִאשֹׁנוֹת occurs six times, five of them in this book. See notes on Isaiah 41:22.

וַחֲדָשׁוֹת אֲנִי מַגִּיד בְּטֶרֶם תִּצְמַחְנָה And I am declaring new things; before they spring into being, The adjective חָדָשׁ means "new," in the sense of something that was not there before. The first accent for is וַֽחֲדָשׁוֹת֙ is gaya or metheg. It's only real function is to caution the reader to slow down a little bit and not slur over the waw-patah. מַגִּיד is a hifil participle from נָגַד "be known, be conspicuous." Notice that attributive participial the phrase אֲנִי מַגִּיד is connected with munah, coming very close to a periphrastic construction: "I am the one who is declaring." תִּצְמַחְנָה qal imperfect from צָמַח "spring up."

אַשְׁמִיע אֶתְכֶם I make them known to you. אַשְׁמִיע is a hifil imperfect from שָׁמַע "hear," and "make heard, make known" in the hifil, often taking on a meaning of "make a proclamation," and is even used as a musical term. Most manuscripts add the furtive patach אַשְׁמִיעַ although L has אַשְׁמִיע, this is certainly one of the minor flaws of L.

The proclamation of the good news of forgiveness is the "new thing" that God declares to us all. And in joy we proclaim the same message to the world.