Isaiah 45:20
הִקָּבְצוּ וָבֹאוּ הִתְנַגְּשׁוּ יַחְדָּו פְּלִיטֵי הַגּוֹיִם לֹא יָדְעוּ הַנֹּשְׂאִים אֶת עֵץ פִּסְלָם וּמִתְפַּלְלִים אֶל אֵל לֹא יוֹשִׁיעַ
Assemble yourselves and come, draw near together, you who have escaped the nations; they have no knowledge, who carry the wood of their graven image and pray to a god that cannot save.
This verse was originally referenced in the prayer Aleinu, though it was later removed from many versions of the prayer. The Radak explains what it is the idolaters don’t know: they have no reason to think that a lump of carved wood could be a god. Nevertheless, they carry it around and pray to it. In the end, of course it is powerless to save them.