From a natural POV, the Pool of Bethesda operated like this.
In digs conducted in the 19th century, a large tank situated about 100 feet north-west of St. Anne’s Church was discovered, which was identified as the Pool of Bethesda. Further archaeological excavation in the area, in 1964, discovered the remains of churches built during the Byzantine and Crusader periods, as well as a temple to Asclepius and Serapis built during Hadrian’s remodelling of Jerusalem as
Aelia Capitolina, the small healing pools of the
asclepieion, the other of the two large pools, and the dam between them. It was discovered that the Byzantine construction was built in the very heart of Hadrian’s construction, and contained the healing pools.
There were two large basins: the northern pool, measuring 53 x 40 meters, which served as a reservoir (
otṣar) for collected rainwater, and the southern pool (47 x 52 meters) which served as the ritual pool (
miqveh). The two pools would have been surrounded by porticos on all four sides, with an additional portico extending across the massive 6-meter barrier wall separating the two basins (cf. John 5:2 “
Now there is in Jerusalem by the sheep gate a pool, which is called in Hebrew Bethesda, having five porticoes”). This wall was partly hewn into the rock and partly built of alternating courses of well-dressed header-and-stretcher ashlars with smoothed exteriors.
A flight of steps facilitated access down to the very base of the pool, depending on the amount of water available there for bathing. These extended down along the entire western side of the southern pool (53 meters in length), with sets of steps in groups of one to six extending between landings. The landings at different intervals would have been used for the placing of the beds of disabled people.
Within the massive barrier wall was a vertical shaft which led to a horizontal tunnel with a sluice gate at the bottom, which meant that the water of the
otṣar to the north could easily have come into contact with with the water of the
miqveh to the south by simply lifting the sluice gate. Further on, at the lower level of the tunnel, there was a covered trough in which more than 1 cubic meter of valid water could have ‘mingled’ with the added water, before then rising and replenishing the waters of the southern pool. A sluice gate was opened at the far end of this trough when necessary, which then, in turn, led to a covered channel that helped drain surplus water away to the south.
It is thought that the pool would have bubbled and frothed when the water was drained into the southern pool, which was what John was describing when the waters were “
stirred up.” In addition, layers of bright red soil trapped between geological layers, seen within the lower part of this area, may have contributed to the picture provided by early Christian writers such as Eusebius and Eucherius regarding the color of the stirred-up waters (Eusebius describes it as “
of a ruddy color,” while Eucherius calls it “
reddish”).
