Model Behavior of the Prophet (Kitab Al-Sunnah)
Dawud :: Book 40 : Hadith 4730
Narrated Anas ibn Malik:
When the Prophet of Allah (peace_be_upon_him) was lifted to the heavens (for travelling) in Paradise, or as he said, a river whose banks were of transparent or hollowed pearls was presented to him. The angel who was with him struck it with his hand and took out musk. Muhammad (peace_be_upon_him) then asked the angel who was with him: What is this? He replied: It is al-Kawthar which Allah has given you.