Numbers 5:26

23 The priest shall write these curses in a book, and he shall blot them out into the water of bitterness:

24 and he shall make the woman drink the water of bitterness that causes the curse; and the water that causes the curse shall enter into her [and become] bitter.

25 The priest shall take the meal-offering of jealousy out of the woman`s hand, and shall wave the meal-offering before Yahweh, and bring it to the altar:

26 and the priest shall take a handful of the meal-offering, as the memorial of it, and burn it on the altar, and afterward shall make the woman drink the water.

27 When he has made her drink the water, then it shall happen, if she be defiled, and have committed a trespass against her husband, that the water that causes the curse shall enter into her [and become] bitter, and her body shall swell, and her thigh shall fall away: and the woman shall be a curse among her people.

28 If the woman isn`t defiled, but be clean; then she shall be free, and shall conceive seed.

29 This is the law of jealousy, when a wife, being under her husband, goes aside, and is defiled;