It is narrated from Hazrat Anas bin Malik (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: Sidrat al-Muntaha was presented before me on the seventh heaven. Its fruits were as large as the jars of a place called "Hajr," and its leaves were as big as the ears of an elephant. At its root, there were two apparent and two hidden rivers flowing. I asked Jibreel (peace be upon him), "What are these?" He replied, "The hidden rivers are in Paradise, and the apparent rivers are the Nile and the Euphrates."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 12673