פירוש על עבודה זרה 90:10

The rabbis understand that Deuteronomy 7:5 mandates cutting down the idolatrous trees as soon as the Israelites enter the land. They then are supposed to go conquer the land and only afterwards are they mandated to destroy the idols. This is also learned from Deuteronomy 12:3. The verse says to tear down their altars and dash in pieces their pillars. It does not mandate destroying them utterly. But we know that such destruction must be done. The answer is that at first they are torn down. Only later are they to be utterly destroyed.