Numbers 5:17-18

17He must pour some holy water into a bowl that someone has made from clay. He must take some dust from the floor of God's Tent. And he must put the dust into the water.

18Then the priest must bring the woman in front of the Lord. The priest must make the woman's hair free. He must put into her hands the grain offering. That is the offering because the man does not trust his wife. The priest must hold the bowl that contains the bitter water. The bitter water brings a curse.