Numbers 5:17

15then the man shall bring his wife to the priest, and shall bring her offering for her: one tenth of an ephah of barley meal. He shall pour no oil on it, nor put frankincense on it, for it is a meal offering of jealousy, a meal offering of memorial, bringing iniquity to memory.

16The priest shall bring her near, and set her before the LORD.

17The priest shall take holy water in an earthen vessel; and the priest shall take some of the dust that is on the floor of the tabernacle and put it into the water.

18The priest shall set the woman before the LORD, and let the hair of the woman’s head go loose, and put the meal offering of memorial in her hands, which is the meal offering of jealousy. The priest shall have in his hand the water of bitterness that brings a curse.

19The priest shall cause her to take an oath and shall tell the woman, “If no man has lain with you, and if you haven’t gone aside to uncleanness, being under your husband’s authority, be free from this water of bitterness that brings a curse.