Ezekiel 47:12

“And by the river on its bank, on this side and on that side, will grow every tree for food, whose leaf will not wither, nor will its fruit fail. It will bring forth firstfruits every month because its waters issue out of the sanctuary. And its fruit will be for food and its leaf for healing.”

The final concluding picture emphasises that this is not to be taken totally literally. On both sides of the river will grow every tree for food. We are in a new Eden (Genesis 2:9). And the trees which grow will be such trees as man has never known. They will be renewed every month, producing, monthly, first firstfruits, and then a harvest, and yet their leaves will not wither. And this will be because they are fed by water from the sanctuary. Their fruit will be for food and their leaf for healing. They are God's trees and God's provision in a unique way.

Here we are clearly in a Paradise restored, with hugely abundant supplies. The idea of healing is not because men will continually need to be healed, but because having been initially healed their health will be continually maintained. It demonstrates their continual wellbeing in the only way that men of that day could understand.

So the whole glorious picture is of God from His heavenly sanctuary beginning a flow of blessing (water was always a sign of blessing) which will grow and grow, bringing life and fruitfulness wherever it goes and producing a new and better Eden with all that man can need, a picture that is taken up and expanded in Revelation which has these verses very much in mind.