They sacrifice on the tops of the mountains, And burn incense on the hills, under oaks and poplars and terebinths, Because its shade is good. Therefore your daughters play the prostitute, And your brides commit adultery.
God had specifically commanded that upon their entry into Canaan, the Israelites should "utterly destroy" all of the places of pagan worship on the mountaintops and high hills and under every green tree  (Deuteronomy 12:2); but instead of obeying God, they set up their own pagan idol worship in exactly the same places (2 Kings 17:10,11).