Answer:
In the poem Beowulf, there is a reference to the rusting of cups and pitchers in the mead hall, Heorot. This is due to a curse that has been placed upon the hall by Grendel's mother, seeking revenge for her son's death at the hands of Beowulf. The curse causes the iron in the cups and pitchers to rust, symbolizing the decay and corruption that has overtaken the hall.
It is important to note that in the context of the poem, the rusting of the cups and pitchers is not a natural occurrence, but rather a supernatural one caused by the curse. This reflects the Anglo-Saxon belief in the power of curses and magic, and the idea that supernatural forces can have a tangible effect on the physical world.
Overall, the rusting of the cups and pitchers in Beowulf serves as a symbol of the decay and corruption that has overtaken Heorot, and the curse placed upon the hall by Grendel's mother serves to heighten the sense of supernatural danger and suspense in the poem.