To make the Heart Tender (Ar-Riqaq)

Bukhari :: Book 8 :: Volume 76 :: Hadith 580

Narrated Ibn 'Abbas:

The word 'Al-Kauthar' means the abundant good which Allah gave to him (the Prophet Muhammad). Abu Bishr said: I said to Said, "Some people claim that it (Al-Kauthar) is a river in Paradise." Said replied, "The river which is in Paradise is one item of that good which Allah has bestowed upon him (Muhammad)."