Isaiah 1:29

For they shall be ashamed -That is, when they see the punishment that their idolatry has brought upon them, they shall be ashamed of the folly and degradation of their worship. Moreover, the gods in which they trusted shall yield them no protection, and shall leave them to the disgrace and confusion of being forsaken and abandoned. Of the oaks -Groves, in ancient times, were the favorite places of idolatrous worship. In the city of Rome, there were thirty-two groves consecrated to the gods. Those were commonly selected which were on hills, or high places; and they were usually furnished with temples, altars, and all the implements of idolatrous worship.