I typically think of this song with the previous hymn (#207) because of their possibilities sharing the same tune. They also both tell a story in the first 2 verses, and then the 3rd verse reminds of the wonder, joy, promise, and excitement for why that humble birth story is so amazing. That 3rd verse is fabulous, because it contains one of the best messages in all the hymns: "No ear may hear his coming; But in this world of sin, Where meek souls will receive him, still The dear Christ enters in." It is similar to the phrase I like of "Wise men still seek Him." We must seek for Him, and be ready and open to receive Him as we find Him.
From the history book
The author Phillips Brooks was a Harvard-trained minister who based this hymn on memories of a visit to the Holy Land. He spent Christmas in Bethlehem in 1865. Three years later he wrote this hymn. I love that--he wrote about that little town, having actual memories of being there. The composer was the superintendent of Brooks' Sunday School as well as the church organist. There were two other verses, though Brooks himself removed the fourth. Some hymnals still print the 5th verse, as the 4th.