Get yourself up on a high mountain, O Zion, bearer of good news, Lift up your voice mightily, O Jerusalem, bearer of good news; Lift it up, do not fear. Say to the cities of Judah, “Here is your God!” (Isaiah 40:9)
good news . . . Jerusalem . . . good news. Like a messenger on a mountain, to be seen and heard by all, the prophet called on the city to proclaim loudly to the rest of Judah’s cities the good news of God’s presence there.
Behold your God! The restoration of Israel to the land is to include the resumption of God’s presence in Jerusalem after many centuries.(Commentary by John MacArthur)