The pool of Siloam is referenced only twice in the Bible. Both of its occurrences are recorded in the gospel of John (John 9:7, 11).
Siloam's pool is famous as the place where Jesus, walking with his disciples, noticed a man who was born blind. He then decided, out of mercy and compassion, to make the man whole even though the person was not asking to be healed. In fact, according to Scripture, the blind man had no idea who it was who miraculously gave him sight! All he knew was that someone told him to wash at Siloam and, when he did, he could see.
And He said to him, "Go and wash in the pool of Siloam" (which is, by interpretation, "Sent"). Then he went and washed, and came from there seeing . . .
Then they (the person's neighbors) said to him, "How were your eyes opened?" He answered and said, "A Man called Jesus made clay, and applied it to my eyes, and said to me, 'Go to the pool of Siloam and wash . . .'" (John 9:7 - 11, HBFV).
The pool of Siloam was originally made by King Hezekiah, ruler of the Kingdom of Judah from 715 to 686 B.C. (2Chronciles 32:30, 2Kings 2:20). It was constructed so that the city of Jerusalem, naturally deficient in water, would be better able to survive a siege from the mighty Assyrian Empire. It was the Assyrians under King Shalmaneser V who, in 723 B.C., conquered the Northern Ten Tribes of Israel's capital at Samaria and took the people captive.
The Biblical Siloam pool was believed to have been found in Autumn 2004 when workers, digging for a new sewer line, uncovered several stone steps. Archaeologists were immediately notified when the steps were found. Subsequent excavations confirmed the authenticity of the location. Before this discovery it was believed that a Byzantine reconstruction, less than 70 yards away, was the location mentioned in the Gospel of John.
The pool is located on the southern slope of the city of David (the original site of Jerusalem) and is just outside the walls of the Old City. It was fed by the waters of the Gihon springs, which were carried to it by two aqueducts. The related tower, mentioned only in the book of Luke (Luke 13:4), is believed to have been part of the city wall near the waters.
Interestingly, water from Siloam was combined with the ashes of a special sacrifice and used by temple priests to perform a unique cleansing ceremony (Numbers 19). According to Jewish tradition, the water itself was retrieved for the religious rite by children riding bulls.
Tradition also states that on the eighth day of the Feast of Tabernacles (known as the Last Great Day), a golden vessel was filled with water from the pool of Siloam and taken to the temple. When the water reached the altar it was poured out before God with much rejoicing.
Jesus referred to this tradition involving the pool when he stated, on the Last Great Day, "If anyone thirsts, let him come to Me and drink. The one who believes in Me, as the scripture has said, out of his belly shall flow rivers of living water" (John 7:37 - 38).