Why does it say "ha'Mizbechos Ma'ase Yadav"?
Radak: It does not say that the Mizbechos are Ma'ase Yadav, for man made all Mizbechos! Rather, ha'Mizbechos is Samuch to Ma'ase Yadav; Ma'ase Yadav are of (for) the idols. He makes the Mizbechos for them, and serves on them Lishmam 1 (for their sake). Even though it is Samuch, it has the prefix Hei ha'Yedi'ah (to identify). We find "ha'Mizbe'ach Beis Kel" (Melachim II, 23:17) and similar verses.
Malbim: This connects to the previous verse. Those who totally denied Hashem and said that the idol created everything, they built altars for it and turned only to it.
Our text says 'la'Shamayim'; we fixed the text based on Kli Paz. (PF)
Why does it say "va'Asher Asu"?
Radak: The matter is repeated in different words.
Malbim: The second group of idolaters admitted to Hashem's existence, but they denied His Hashgachah, and said that the idol is an intermediary between them and Hashem. They did not build altars for it; they primarily served the Creator - "uv'Chol Makom Muktar Mugash li'Shmi" (Mal'achi 1:11). They merely put the idol in front of their eyes, to see it when they serve. After they will admit to Hashgachah, they will not put it in front of their eyes to direct Avodas Hashem.
Why does it say "Lo Yir'eh"?
Rashi: They will not be important in his eyes.
