The "pool of Bethesda" (Jn. 5:2, 4, 7) and the "pool of Siloam" (Jn. 9:7, 11) are also mentioned. Isaiah (Isa. 35:7) says, "The parched ground shall become a pool." This is rendered in the Revised Version "glowing sand," etc. (marg., "the mirage," etc.). The Arabs call the mirage "serab," plainly the same as the Hebrew word sarab, here rendered "parched ground." "The mirage shall become a pool", i.e., the mock-lake of the burning desert shall become a real lake, "the pledge of refreshment and joy." The "pools" spoken of in Isa. 14:23 are the marshes caused by the ruin of the canals of the Euphrates in the neighbourhood of Babylon.
The cisterns or pools of the Holy City are for the most part excavations beneath the surface. Such are the vast cisterns in the temple hill that have recently been discovered by the engineers of the Palestine Exploration Fund. These underground caverns are about thirty-five in number, and are capable of storing about ten million gallons of water. They are connected with one another by passages and tunnels.