I think this song stood out more in my mind as I grew up because I liked the tune. The words are, of course, great, and about when the Lord will come again. Calling people (or Israel) to repentance so they can be there when He comes again...or at least return to Him one day if they are not on earth for the Second Coming. My favorite lines are actually the 3rd (which is repeated in the 4th):
And within her walls rejoice
For your coming Lord is nigh
Zion's walls shall ring with praise
For the girl who has spent many years (and literally hundreds of blog entries on this blog as well as my journal blog!) trying to find happiness, joy, and reasons to rejoice, I absolutely adore lines in song about joy and rejoicing!
From the history book
It talks about how it is not just a symbolic invitation of Zion (the pure in heart), but for the author it was a literal invitation, one he issued on the 3 missions he served (all of them in Great Britain and Ireland) where he encouraged them to join the Saints in America.
I did not know this about the tune. Apparently this was a very popular tune for the early LDS and sang many songs to it (including "O My Father"  and "What Was Witnessed in the Heavens" ). Even more so, I had no idea that other denominations sing "What a Friend We Have in Jesus" to this. I have only ever known the first line of that song--and never connected that it is the same tune as the first line of this hymn! But it is nice to know I was in very good company by liking the tune so much as I grew up.'