The water of jealousy is a phrase for the water used in the Mosaic procedure concerning a wife suspected of unfaithfulness. The water served a symbolic and ministerial role within an oath and solemn curse before the Lord.
The suspected woman stood before the priest, who mixed holy water with dust from the sanctuary floor, wrote and blotted out the curses, and gave her the potion to drink after she answered “Amen.” The procedure distinguished innocence from guilt by divine judgment.
The water itself was described as harmless rather than a natural poison. The essential element was the oath and imprecation, with the water serving as their appointed symbol and instrument.