And the priest shall take holy water in an earthen vessel; and of the dust that is in the floor of the tabernacle the priest shall take, and put it into the water: Holy water - Water out of the laver, called holy because consecrated to sacred uses. This is the most ancient case of the trial by ordeal. See at Numbers 5:31 (note).
In an earthen vessel - Supposed by the Jews to be such as had never been previously used.
Dust that is in the floor - Probably intended to point out the baseness of the crime of which she was accused.