One-fifth of Booty to the Cause of Allah (Khumus)

Bukhari :: Book 4 :: Volume 53 :: Hadith 341

Narrated Anas bin Malik:

When the cup of Allah's Apostle got broken, he fixed it with a silver wire at the crack. (The sub-narrator, 'Asim said, "I saw the cup and drank (water) in it.")