Tolkien's witty humor could also be proven by the hilarious quotes in The Hobbit and The Lord of the Rings books.
Some examples: These crack me up everytime I read them:
1) This is when Aragorn, Gimli, and Gandalf discover Merry and Pippin and start asking them lots of questions (in The Two Towers) "One thing you have not found in your hunting, and that's brighter wits"- that's Pippin.
2) "You don't know your danger, Theoden, These hobbits will sit on the dge of ruin and discuss the pleasures of the table, or the small doings of their fathers, grandfathers, and great-grandfathers and remoter cousins to the ninth degree, if you encourage them with undue patience."-Gandalf
3)"Are we riding far tonight, Gandalf? I don't know how you feel with a small rag-tag dangling behind you; but the rag-tag is tired and will be glad to stop dangling and lie down."- Merry
4)Merry: Do not meddle in the affairs of Wizards, for they are subtle and quick to anger
Pippin: But our whole life for months has been one long meddling in the affairs of Wizards!
5)Pippin: All right! . . . I know I can't have it, with old Gandalf sitting on it, like a hen on an egg. But it doesn't help much to get no more from you than a you-can't-have-it so go-to-sleep!
Merry: Well, what else could I say? I'm sorry, Pippin, but you really must wait until the morning. I'll be as curious as you like after breakfast, and I'll help in anyway I can at wizard-wheedling. But I can't keep awake any longer. If I yawn any more, I shall split at the ears. Good night!
6: Sam: Not a bird!
Gollum: No, no birds. Nice birds! No birds here. There are snakeses, wormses, things in the pools. Lots of things, lots of nasty things. No birds,
7) Sam: What's the need to sniff? The stink nearly knocks me down with my nose held. You stink, and the master stinks; the whole place stinks.
Gollum: Yes, yes, and Sam stinks!!
Sam has a lot of hilarious one-liners in the book and his funny debates with Gollum never fail to crack me up everytime.