Albert Barnes Commentary Isaiah 29:4

"And thou shalt be brought down, and shalt speak out of the ground, and thy speech shall be low out of the dust; and thy voice shall be as of one that hath a familiar spirit, out of the ground, and thy speech shall whisper out of the dust." — Isaiah 29:4 (ASV)

And shalt speak out of the ground - (see the note at Isaiah 8:19). The sense here is that Jerusalem, which had been accustomed to pride itself on its strength, it would be greatly humbled and subdued. Its loud and lofty tone would be changed. It would use the suppressed language of fear and alarm, as if it spoke from the dust or in a shrill, small voice, like the pretended conversers with the dead.

And thy speech shall whisper out of the dust - Margin, ‘Peep,’ or ‘Chirp’ (see the note at Isaiah 8:19).