Many phrases from this story, especially when Glóin and Bilbo discuss the "official" version of their companions' deaths, is taken from the closing chapters of The Hobbit. My title comes from the battle-song sung by Dáin's dwarves as they march on Erebor, particularly the first few lines:
Under the Mountain dark and tall
The King has come unto his hall!
His foe is dead, the Worm of Dread,
And ever so his foes shall fall.
The sword is sharp, the spear is long,
The arrow swift, the Gate is strong;
The heart is bold that looks on gold;
The dwarves no more shall suffer wrong.
Thanks to Linda Hoyland, who checked Bilbo's language for Americanisms.