This phrase refers to those who worship these idols and who claim to be witnesses of the idols' power. Yahweh speaks of their inability to understand the truth as if they were blind. AT: "those who serve as witnesses for these idols are like blind people who know nothing" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This can be stated in active form. AT: "they will be ashamed" or "their idols will put them to shame" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Yahweh is using this question to rebuke those who make idols. This question can be translated as a statement. AT: "Only fools would form a god or cast an idol that is worthless." (See: [[rc://en/ta/man/translate/figs-rquestion]])
The word "worthless" does not distinguish worthless idols from idols that have worth, because all idols are worthless. AT: "cast worthless idols" (See: [[rc://en/ta/man/translate/figs-distinguish]])