Thread creep from tune to lyrics:

How did this song come to be connected with Christmas? I don't see any of the usual references to Christ's birth. I would've considered it a hymn. Yet masato quotes Elizabeth Poston discussing the song's "association with Christmas in the carol services and broadcasts of the choir of King's College, Cambridge." Wonder why they associated it with Christmas. I doubt that it has anything to do with the lore of the Tannenbaum, which if I'm not mistaken (and I certainly may be!) was always an evergreen, not a deciduous fruit tree. How did a fruit tree come to be described in verse as "always green", and thus compared with the ever-constant love of Christ, anyway??

Also, how did the Apple Tree come to invoke (again in Poston's words) "the imagery of the Tree of Life"? The apple has been represented as the fruit of the Tree of Knowledge of Good and Evil (the forbidden fruit) in lore and in art, but I've never before heard of it being associated with the Tree of Life. Anybody know the history of how this came to be?