Rashi on Isaiah
molded Heb. נָסָךְ, an expression of pouring and a molten image (מַסֵּכָה). The ‘nun’ in the word is a radical sometimes omitted, e.g., the ‘nun’ of נשך, biting, and of נגף, plaguing.
Ibn Ezra on Isaiah
Who hath formed, etc. Is there any thoughtlessness like this, to attempt to form a god? God. So called in the sense of him who formed the image.