The Messenger of Allah ﷺ was asked, "What is al-Kawthar?"He replied, "It is a river Allah has granted me," meaning in Paradise, "whiter than milk and sweeter than honey. In it are birds whose necks are like the necks of camels."Umar remarked, "These birds must be plump and delicate!"The Messenger of Allah ﷺ said, "Those who eat them are even finer than they are."
سئل رسول الله ﷺ: ما الكوثر؟ قال: ذاك نهر أعطانيه الله- يعني في الجنة- أشد بياضا من اللبن، وأحلى من العسل، فيها طير أعناقها كأعناق الجزر. قال عمر: إن هذه لناعمة! قال رسول الله ﷺ: أكلتها أحسن منها.
Tirmidhi (2542) reported it from Abd bin Humayd, who said, Abdullah bin Maslama informed us, from Muhammad bin Abdullah bin Muslim, from his father, from Anas bin Malik, and he related it.Its chain is hasan because of Muhammad bin Abdullah bin Muslim, for his hadith is hasan. The discussion of this is given at length in the Book of Faith.