Isaiah 52 was the inspiration for Go Tell it on the Mountain, an African-American spiritual song that has become a classic Christmas Carol. The context in Isaiah is that Israel is enslaved to Assyria, from which they await a salvation. Through Isaiah, God describes the wave of good news of this salvation - starting up high on the mountains and spilling out to become joyful praise everywhere. We now realize that Jesus birth is God’s ultimate plan coming to fruition, and spreading the joy of that salvation continues on through us.