Isaiah 41:26

מִי־הִגִּיד מֵרֹאשׁ וְנֵדָעָה וּמִלְּפָנִים וְנֹאמַר צַדִּיק אַף אֵין־מַגִּיד אַף אֵין מַשְׁמִיעַ אַף אֵין־שֹׁמֵעַ אִמְרֵיכֶם׃

26 Who told this from the beginning, so we might know? And beforehand, so that we could say, "He is righteous." No, there was no one who told. No, there was no one who proclaimed. No--there was no one listening to your sayings!

מִי־הִגִּיד מֵרֹאשׁ וְנֵדָעָה Who told this from the beginning, so we might know? The hifil perfect הִגִּיד begins a challenge: Which of your gods foretold anything? וְנֵדָעָה is a qal cohortative; note the cohortative ה- ending. The Mp note says that מֵרֹאשׁ occurs 14 times (see comments on 40:21). Another Mp note says that וְנֵדָעָה occurs just twice (cf. Isaiah 5:19).

וּמִלְּפָנִים וְנֹאמַר צַדִּיק And beforehand, so that we could say, "He is righteous." The odd form וּמִלְּפָנִים "and from to the פָנִים (faces)" is a way of saying "and right in front of someone," or "before the time of someone." וְנֹאמַר is a qal imperfect, and parallel with וְנֵדָעָה above so naturally taken as another cohortative. צַדִּיק is "righteous," and here the question is whether any pagan god could be called righteous in the way that the true God is righteous. Like Jesus wanting mankind to know that his Father is "the only true God" (John 17:3), here the Lord wants us to know that no pagan deity can ever be called the true God. They don't just fail to be righteous, they fail to be "right" about anything at all. The question is this: Show us anybody in your pantheon who ever did anything at all!

אַף אֵין־מַגִּיד No, there was no one who told. אַף is an emphatic conjunction, here it emphasizes the negative אֵין. The participle מַגִּיד is attributive, "one who told." The Mp note for אֵין־מַגִּיד says that the phrase is technically hapax, but it occurs with a waw in Genesis 41:24.

אַף אֵין מַשְׁמִיעַ No, there was no one who proclaimed. Another אַף emphasizes another אֵין; and this is another attributive participle, the hifil מַשְׁמִיעַ is "caused to be heard" or "proclaimed."

אַף אֵין־שֹׁמֵעַ אִמְרֵיכֶם No--there was no one listening to your sayings! A third אַף emphasizes a third אֵין as Isaiah turns the previous hifil מַשְׁמִיעַ into a simple qal participle שֹׁמֵעַ "one who heard." An אִמְרָה is a "speech" or any "utterance." No one listened to them beause the false gods have said nothing at all. They are as dumb as they are dumb.