19 Then the priest shall make her take an oath, saying, 'If no man has lain with you, and if you have not turned aside to uncleanness, while you were under your husband's authority, be free from this water of bitterness that brings the curse. 20 But if you have gone astray, though you are under your husband's authority, and if you have defiled yourself, and some man other than your husband has lain with you, 21 then' (let the priest make the woman take the oath of the curse, and say to the woman) 'the Lord make you an execration and an oath among your people, when the Lord makes your thigh fall away and your body swell; 22 may this water that brings the curse pass into your bowels and make your body swell and your thigh fall away.' And the woman shall say, 'Amen, Amen.'
Matthew Henry's Commentary on Numbers 5:19-22
Commentary on Numbers 5:11-31
(Read Numbers 5:11-31)
This law would make the women of Israel watch against giving cause for suspicion. On the other hand, it would hinder the cruel treatment such suspicions might occasion. It would also hinder the guilty from escaping, and the innocent from coming under just suspicion. When no proof could be brought, the wife was called on to make this solemn appeal to a heart-searching God. No woman, if she were guilty, could say "Amen" to the adjuration, and drink the water after it, unless she disbelieved the truth of God, or defied his justice. The water is called the bitter water, because it caused the curse. Thus sin is called an evil and a bitter thing. Let all that meddle with forbidden pleasures, know that they will be bitterness in the latter end. From the whole learn, 1. Secret sins are known to God, and sometimes are strangely brought to light in this life; and that there is a day coming when God will, by Christ, judge the secrets of men according to the gospel, Romans 2:16. 2 In particular, Whoremongers and adulterers God will surely judge. Though we have not now the waters of jealousy, yet we have God's word, which ought to be as great a terror. Sensual lusts will end in bitterness. 3. God will manifest the innocency of the innocent. The same providence is for good to some, and for hurt to others. And it will answer the purposes which God intends.