In the aftermath of Beowulf’s battle with Grendel’s mother, the narrator uses a simile to describe a mysterious sword that Beowulf found in her lair: 

Now that sword began,
from blood of the fight, in battle-droppings, 
war-blade, to wane: 'twas a wondrous thing 
that all of it melted as ice is wont 
when frosty fetters the Father loosens, 
unwinds the wave-bonds, wielding all 
seasons and times: the true God he!
Nor took from that dwelling the duke of the 
Geats precious things, though a plenty he saw, 
save only the head and that hilt withal 
blazoned with jewels: the blade had melted, 
burned was the bright sword, her blood was so hot, 
so poisoned the hell-sprite who perished within there.

When Beowulf attempted to attack Grendel’s mother with a sword that was gifted to him by Unferth, the blade had no effect. After some time fighting her by hand, he finds a large sword once used by giants, which he uses to decapitate her. Miraculously, the sword melts away at the end of the battle, leaving behind only its jeweled hilt. The narrator notes that “all of it melted as ice,” drawing a comparison between this “wondrous” event and a far more ordinary natural process. The melting away of the sword suggests that it is no ordinary, human-made object, but rather one of magical origins.