The Hobbit Chapter 9

The significance of Bilbo's Hobbit-hole, as mentioned in Chapter Nine is Bilbo's homesickness..... he misses the normalcy, comfort, and protection of his home.

"I am like a burglar that can't get away, but must go on miserably burgling the same house day after day," he thought. "This is the dreariest and dullest part of all this wretched, tiresome, uncomfortable adventure! I wish I was back in my hobbit-hole by my own warm fireside with the lamp shining!"