Anas ibne-Mãlik (Ra) narrates that Rasúlullãh (saw) said: While I was passing through Paradise, I found myself by a river on the two sides of which were domes of hollow pearls. I asked: What is this O Jibraíl? He replied: This is the Kauthar that your Rabb granted. Its soil was the most excellent musk.
(Bukhãrí)