Anas ibn Mālik (may Allah be pleased with him) reported that the Prophet (ﷺ) ﷺ said: “I entered Paradise and found myself by a river whose banks had tents of pearl. I placed my hand in the bed of the flowing water and a most fragrant musk. I said: ‘O Jibrīl, what is this?’ He said: ‘This is al-Kawthar that Allah has given you, or: that your Lord has given you.’” Reference: Musnad Aḥmad 191