There is significant biblical allusion going on in these last two paragraphs. The last two are very short. The third from the end discusses the fact that the men were walking in silence and were just remembering. This paragraph is important because it set up the last two... with a different biblical allusion. This paragraph referred to
A time to break down, and a time to build up. Yes. A time to keep silence and a time to speak. Yes, all that.
These "times" are from Ecclesiastes 3, you may remember that Montag is now that book of the bible. This passage is significant because it means that just like all things must die, there is also time for rebirth. This gives hope when times are tough because it means new times are coming in the future.
In the very last two paragraphs, he refers to the "tree of life", the "twelve manner of fruits" and the "healing of the nations".
This refers to Revelation 22 when God will restore the Garden of Eden. When God created the world, it was perfect. When the world is over, He will re-create His perfection. Here is what Revelation 22:1-4 says:
1 Then the angel showed me the river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb 2 down the middle of the great street of the city. On each side of the river stood the tree of life, bearing twelve crops of fruit, yielding its fruit every month. And the leaves of the tree are for the healing of the nations. 3No longer will there be any curse. The throne of God and of the Lamb will be in the city, and his servants will serve him. 4They will see his face, and his name will be on their foreheads. 5There will be no more night. They will not need the light of a lamp or the light of the sun, for the Lord God will give them light. And they will reign for ever and ever.
The effort of Bradbury here is to shed hope on this situation. He is showing that the pain and problems of the last society are over and now is the time for healing and building of a new city.