Twelve kinds of fruit from a single tree is a scientific impossibility in the world we know. The same tree ceaselessly yielding new fruit each month is also scientifically impossible in the world we know. The God who created all trees (Genesis 1:11–12) is certainly able to generate such trees. Yet the point of the passage is not that the Lord will literally provide such trees; instead, here is symbolic portrayal of the abundance of life that his children receive from him. (For the significance of the number twelve, see on Revelation 21:16.) The New Jerusalem knows no shortage of any kind, though it is inhabited by innumerable multitudes. Similarly, the abundance is not seasonal (with a possible hungry month) but is consistent, like the manna of the desert was (Exodus 16:4–5; Deuteronomy 8:3).
2 through the middle of the street of the city; also, on either side of the river, the tree of life with its twelve kinds of fruit, yielding its fruit each month. The leaves of the tree were for the healing of the nations.