If anyone was looking for an historic understanding of Advent devotion, I’d heartily recommend them to look to the work of St. Ephraim the Syrian. He wrote a great Hymn for Christmas that you can see: here
It’s a LOT longer than most of the hymns we’ve come to be familiar with, but it is rich in theology and mentions many of the things discussed on this site so far for Advent and Christmas.
” In the winter which strips the fruit of the branches off from the barren vine, Fruit sprang up (Isa. 5:2) unto us; in the cold that bares all the trees, a shoot was green for us of the house of Jesse. In December when the seed is hidden in the earth, there sprouted forth from the Womb the Ear of Life. In March when the seed was sprouting in the air, a Sheaf (Lev. 23:10) sowed itself in the earth. The harvest thereof, Death devoured it in Hell; which the Medicine of life that is hidden therein did yet burst open! In March when the lambs bleat in the wilderness, into the Womb the Paschal Lamb entered! Out of the stream whence the fishers came up, He was baptized and came up Who incloses all things in his net; out of the stream the fish whereof Simon took, out of it the Fisher of men came up, and took him. With the Cross which catches all robbers, He caught up unto life that robber! (Lk. 23:43) The Living by His death emptied Hell, He unloosed it and let fly away from it entire multitudes! The publicans and harlots, the impure snares, the snares of the deceitful fowler the Holy One seized! The sinful woman, who was a snare for men, He made a mirror for penitent women! The fig that cast its fruit, that refused fruit, offered Zacchæus as fruit; the fruit of its own nature it gave not, but it yielded one reasonable fruit! The Lord spread His thirst over the well, and caught her that was thirsty with the water that He asked of her. He caught one soul at the well, and again caught with her the whole city: (Jn. 4:42) twelve fishers the Holy One caught, and again caught with them the whole world. As for Iscariot, that escaped from His nets, the strangling halter fell upon his neck! His all-quickening net catches the living, (Mt. 13:47) and he that escapes from it escapes from the living.”
The imagery of the Christmas tree is there (presumably predating the object itself) “With the tree wherewith he [Satan] slew us (the tree in the garden & the cross), He [Christ] delivered us.”
and
“Our Saviour’s day— is praised far above it, a tree planted in the world.— For His Death is as the root in the earth; His Resurrection as the head in heaven; on all sides His words reach as boughs; likewise His Body as fruit for the eaters.”
Perhaps my favourite image in the hymn from what I’ve read so far, is the St. Ephraim’s image of justification, wherein he writes ” Praise we Him Who grafted into our tree His fruit.” Christ’s righteousness is the good fruit which he grafts onto our trees!