The Messenger of Allah ﷺ said, "Al-Kawthar is a river in Paradise. Its banks are of gold, and it flows over pearls and rubies. Its soil is more fragrant than musk, its water sweeter than honey, and whiter than snow."
قال رسول الله ﷺ: الكوثر نهر في الجنة، حافتاه من ذهب ومجراه على الدر والياقوت تربته أطيب من المسك وماؤه أحلى من العسل، وأبيض من الثلج.
Tirmidhi (3361) and Ibn Majah (4334) both narrated it from Muhammad bin Fudayl, from Ata bin Saaib, from Muharib bin Dithar, from Ibn Umar, who related it, and their wording is identical. Ata bin Saaib had his memory become confused later in life, and it is not known whether Muhammad bin Fudayl heard from him before or after this confusion set in. However, he is corroborated, as will be seen in the hadith that follows. Tirmidhi said, "Hasan sahih." I say, rather it is hasan only.