The Lord make thee a curse and an oath - Let thy name and punishment be remembered and mentioned as an example and terror to all others. Like that mentioned Jeremiah 29:22, Jeremiah 29:23; : "The Lord make thee like Zedekiah, and like Ahab, whom the king of Babylon roasted in the fire, because they have committed villany in Israel, and have committed adultery with their neighbors' wives." - Ainsworth.
The trial of jealousy. Since the crime of adultery is especially defiling and destructive of the very foundations of social order, the whole subject is dealt with at a length proportionate to its importance. The process prescribed has lately been strikingly illustrated from an Egyptian “romance,” which refers to the time of Rameses the Great, and may therefore well serve to illustrate the manners and customs of the Mosaic times. This mode of trial, like several other ordinances, was adopted by Moses from existing and probably very ancient and widely spread institutions.
Numbers 5:15
The offering was to be of the cheapest and coarsest kind, barley (compare 2 Kings 7:1, 2 Kings 7:16, 2 Kings 7:18), representing the abused condition of the suspected woman. It was, like the sin-offering Leviticus 5:11, to be made without oil and frankincense, the symbols of grace and acceptableness. The woman herself stood with head uncovered Numbers 5:18, in token of her shame.
Numbers 5:17
The dust that is in the floor of the tabernacle - To set forth the fact that the water was endued with extraordinary power by Him who dwelt in the tabernacle. Dust is an emblem of a state of condemnation Genesis 3:14; Micah 7:17.
Numbers 5:19
Gone aside - literally, “gone astray from” thy husband by uncleanness; compare Hosea 4:12.
Numbers 5:23
Blot them out with the bitter water - In order to transfer the curses to the water. The action was symbolic. Travelers speak of the natives of Africa as still habitually seeking to obtain the full force of a written charm by drinking the water into which they have washed it.
Numbers 5:24
Shall cause the woman to drink - Thus was symbolised both her full acceptance of the hypothetical curse (compare Ezekiel 3:1-3; Jeremiah 15:16; Revelation 10:9), and its actual operation upon her if she should be guilty (compare Psalm 109:18).
Numbers 5:26
The memorial thereof - See the marginal reference. “Memorial” here is not the same as “memorial” in Numbers 5:15.
Numbers 5:27
Of itself, the drink was not noxious; and could only produce the effects here described by a special interposition of God. We do not read of any instance in which this ordeal was resorted to: a fact which may be explained either (with the Jews) as a proof of its efficacy, since the guilty could not be brought to face its terrors at all, and avoided them by confession; or more probably by the license of divorce tolerated by the law of Moses. Since a husband could put away his wife at pleasure, a jealous man would naturally prefer to take this course with a suspected wife rather than to call public attention to his own shame by having recourse to the trial of jealousy. The trial by red water, which bears a general resemblance to that here prescribed by Moses, is still in use among the tribes of Western Africa.