Isaiah 12:3

Draw water] Under a figure it is indicated that there shall be a continual supply of divine protection and deliverance. Or, if we follow the Talmud, there may be an allusion to the ceremonial of the Feast of Tabernacles, on the last day of which water was drawn from the pool of Siloam by the priests and poured at the altar of burnt-offering (see John 7:37).