Sahih Bukhari | Volume 8 | Hadith Number 591
Narrated by Haritha bin Wahb
I heard the Prophet mentioning the Lake-Fount (Al-Kauthar), saying, "(The width of the Lake-Fount) is equal to the distance between Medina and Sana' (capital of Yemen)." Haritha said that he heard the Prophet saying that his Lake-Fount would be as large as the distance between Sana' and Medina. Al-Mustaurid said to Haritha, "Didn't you hear him talking about the vessels?" He said, "No." Al-Mustaurid said, "The vessels are seen in it as (numberless as) the stars."