Q 127: What is the textual proof from the Glorious Qur'an that the Cistern exists?
A--- Allah the Almighty says to His Prophet Muhammad (Peace be upon him): {Verily, We have granted you (O Muhammad (Peace be upon him)) Al-Kauthar (a river in Paradise)}. (Al-Kauthar, 1)
Reference: 200 FAQ On Muslims Belief - Shiekh Hafiz Ibn Ahmed Al Hakami