Son of man, set thy face toward the mountains of Israel, and prophesy against them, Set thy face toward the mountains of Israel - This is a new prophecy, and was most probably given after the four hundred and thirty days of his lying on his left and right side were accomplished. By Israel here, Judea is simply meant; not the ten tribes, who had long before been carried into captivity. Ezekiel uses this term in reference to the Jews only.
The mountains may be addressed here particularly, because it was on them the chief scenes of idolatry were exhibited.