Numbers 5:17

13 by sleeping with another man, and it is concealed from her husband and her impurity is undetected (since there is no witness against her and she was not caught in the act),

14 and if a feeling of jealousy comes over her husband and he suspects his wife who has defiled herself—or if a feeling of jealousy comes over him and he suspects her even though she has not defiled herself—

15 then he is to bring his wife to the priest. He must also bring for her an offering of a tenth of an ephah of barley flour. He is not to pour oil over it or put frankincense on it, because it is a grain offering for jealousy, an offering of memorial as a reminder of iniquity.

16 The priest is to bring the wife forward and have her stand before the LORD.

17 Then he is to take some holy water in a clay jar and put some of the dust from the tabernacle floor into the water.

18 After the priest has the woman stand before the LORD, he is to let down her hair and place in her hands the grain offering of memorial, which is the grain offering for jealousy. The priest is to hold the bitter water that brings a curse.

19 And he is to put the woman under oath and say to her, ‘If no other man has slept with you and you have not gone astray and become defiled while under your husband’s authority, may you be immune to this bitter water that brings a curse.

20 But if you have gone astray while under your husband’s authority and have defiled yourself and lain carnally with a man other than your husband’—

21 and the priest shall have the woman swear under the oath of the curse—‘then may the LORD make you an attested curse among your people by making your thigh shrivel and your belly swell.

Read all of Numbers 5