How we cite our quotes: (Book.Chapter.Paragraph).
Quote #1
Stone-hard are the Dwarves in labour or journey, but this endless chase began to tell on [Gimli], as all hope failed in his heart. Aragorn walked behind him, grim and silent, stooping now and again to scan some print or mark upon the ground. Only Legolas still stepped as lightly as ever, his feet hardly seeming to press the grass, leaving no footprints as he passed; but in the waybread of the Elves he found all the sustenance that he needed, and he could sleep, if sleep it could be called by Men, resting his mind in the strange paths of elvish dreams, even as he walked open-eyed in the light of the world. (3.2.78)
These elves are relentless. They don't age, tire, or even die the way we unfortunate mortals do. Here is Legolas, after days of solid running after orcs, still stepping "as lightly as ever." He doesn't even need to sleep, which is quite efficient if we may say so. But what's really interesting about Legolas's stamina is that his physical youth ties him symbolically to the youth of Middle-earth. Elves are the Firstborn of the races of the world, present when Middle-earth was new and fresh. One way to think of the elves' departure from Middle-earth is as a coming of age story for Tolkien's world. The elves are associated with the early stages of Middle-earth's history, but over the course of The Lord of the Rings, as Middle-earth ages, they aren't needed anymore.
Quote #2
Poor Boromir! I could not see what happened to him. It was a sore trial for such a man: a warrior and a lord of men. Galadriel told me that he was in peril. But he escaped in the end. I am glad. It was not in vain that the young hobbits came with us, if only for Boromir's sake. But that is not the only part they have to play. They were brought to Fangorn, and their coming was like the falling of small stones that starts an avalanche in the mountains. (3.5.88)
When Merry and Pippin first go on Frodo's quest, we don't have a strong sense of what they will bring to the Fellowship. They are merry (no pun intended) and good-hearted, but they also get into a ton of trouble (remember Pippin alerting the orcs to their presence in the Mines of Moria in The Fellowship of the Ring Book 2, Chapter 4?). But with youths like these, it's all about potential. Boromir and Aragorn are proven soldiers. But Merry's and Pippin's futures are blank slates.
Quote #3
I shall miss them. We have become friends in so short a while that I think I must be getting hasty—growing backwards towards youth, perhaps. But there, they are the first new thing under Sun or Moon that I have seen for many a long, long day. I shall not forget them. I have put their names into the Long List. Ents will remember it.
Ents the earthborn, old as mountains,
the wide walkers, water drinking:
and hungry as hunters, the Hobbit children,
the laughing-folk, the little people,they shall remain friends as long as leaves are renewed. Fare you well! (3.10.81)
In Fellowship of the Ring, Gandalf justifies bringing Merry and Pippin along on this Ring quest instead of sturdy soldiers because the point of the quest is not strength of arms but cheer and friendship. After all, it's these powers that will support Frodo through the dark days of his battle with the Ring (see The Fellowship of the Ring Book 2, Chapter 3). Despite the fact that Merry and Pippin are now separated from their hobbit buddies, their continued purpose is not lost on Treebeard. They may be young, but they bring lighthearted laughter to their older, wearier companions.