Having had enough of all this squabbling and bickering over Bilbo's suitability for the task, Gandalf finally lost his temper and decided to remind this company of dwarves of the true nature of his power, just to be clear on the matter. The wizard rose quickly to his feet as the room darkened and his voice boomed through the walls loudly.
"ENOUGH! If I say Bilbo Baggins is our burglar, then our burglar he is!" with a slight sigh under his breath, Gandalf released the power he had summoned and returned the light to the room, his expression softening slightly. 
"Hobbits are remarkably light on their feet, they can pass unseen by most should they choose to. And while the dragon is accustomed to the smell of dwarf, the scent of hobbit is all but unknown to him, which gives us a distinct advantage. You asked me to find the fourteenth member of this company, and I have chosen Mr. Baggins. There’s a lot more to him than appearances suggest, and he’s got a great deal more to offer than any of you know, including himself. You must trust me on this."

"....Very well." Thorin conceded, although somewhat reluctantly, as he glowered up at the wizard. "We will do it your way."
"No, no, no!" Bilbo tried to protest, though it appeared it would do no good, as Thorin simply ignored him, his gaze turning to Balin, the oldest looking dwarf of the company. 
"Give him the contract."