Unfaithfulness

[Num. 5:15] Then shall the man bring his wife unto the priest, and he shall bring her offering for her, the tenth part of an ephah of barley meal; he shall pour no oil upon it, nor put frankincense thereon; for it is an offering of jealousy, an offering of memorial, bringing iniquity to remembrance.
Pour no oil - Only in the sin offering, and so this offering of jealousy were neither oil nor incense offered.
In ancient times when a husband suspected his wife of being unfaithful to him he would warn her not to seclude herself with another man. If she continued to do this, the husband would bring her before the priest for the examination under the rules determining whether she was a sotah. She had to be warn in front of two witnesses and the observed by two witnesses being secluded with another man. The procedure involved her having to drink special water with bitter herbs added while holding the paper of accusation. During the Second Temple period, this was done of the Nicanor 15 steps in the Woman’s Court. She could only be given this test if she consented. If she refused to drink the waters, she was divorced from her husband and considered guilty. If she were guilty, she would get sick and die. If she was guilty, the waters will cause her stomach to distend, if she were innocent, the drink would not effect her. Before the ritual begins, before her guilt or innocence is revealed, a priest humiliates in her by baring her head. The Mishneh on the sotah describes this humiliation in lurid detail. The priest tears the woman’s clothes, baring her bosom. If she wore white, she was forced to change to black. If she wore gold and silver jewelry, nose rings and earrings, they were taken from her. A rope of rushes was tied above her breasts. All who wanted to view her undressed, were allowed. Her presence was a cautionary tale. It is said that a woman’s uncovered hair represents degradation. Later interpretations called women’s head coverings sign of modesty, of dignity, or of respectfulness. Rules concerning the type of the hair covering used and when it is to be worn have always stemmed from the customs of individual communities. Over time, these customs took on the status of Law. Baldness plus a head covering, unquestionably a most sever variation, is said to have certain advantages. The bald woman needn’t worry that any of her hair is exposed in an inappropriate place. She needn’t fear that when she immerses herself in the ritual bath her hair will float to the top, making her immersion invalid. The Talmud says that righteous children will be born to the woman so scrupulous in covering her hair that even the walls of her house cannot see the hairs on her head. G-d promised to remove all shame and humiliation from her by rewarding her with a beautiful male child. In order for this trial to be effective, the husband himself had to be completely blameless in his sexual life. John 8:7.
Remembrance - Or, making the sin known, and not purging it.
It was forbidden to pour any oil upon the sotah offering that was brought at the time of this examination. The woman had to bring both a sacrifice as well as a meal offering.
Applied to the offering brought by the sotah (woman suspected of being unfaithful to her husband.) All other meal offerings had oil and were sprinkled with frankincense. (Meal offerings were oil, incense, salt, leaven, honey; like a pancake.)
The water of purification of sprinkling, read 19:9, water from the laver, which was to be mixed with dust - an emblem of vileness and misery (Gen. 3:14, Ps. 22:15).
In an earthen vessel - This fragile ware was chosen because, after being used, it was broken in pieces (Lev. 6:28, 11:33). All the circumstances of this awful ceremony--her being placed with her face toward the ark--her uncovered head, a sign of her being deprived of the protection of her husband (1 Cor. 11:7) - the bitter potion being put into her hands preparatory to an appeal to G-d the solemn adjuration of the priest (5:19-22), all were calculated in no common degree to excite and appall the imagination of a person conscious of guilt.
Dust - An emblem of vileness and misery. From the floor of the tabernacle - Which made it holy dust, and struck the greater terror into the woman, if she were guilty. She was before the L-rd - Before the Tabernacle with her face towards the ark.
Uncover her head - Partly that she might be made sensible how manifest she and all her ways were to G-d; partly in token of her sorrow for her sin, or at least for any cause of suspicion which she had given.
In her hands - That she herself might offer it, and thereby call G-d to be witness of her innocence.
Bitter - So called either from the bitter taste that the dust gave it, or from the bitter effects of it upon her, if she were guilty. That caused the curse - Not by any natural power, but by a supernatural efficacy.
Curse - It was so called by the effect, because it declared the woman to be accursed, and turned to her destruction.
Charge her an oath - To answer truly to his question, or to declare whether she be guilty or no, and after such oath shall say as follows. That is, a form of cursing, that when they would curse a person, they may wish that they may be as miserable as thou was.
Thy thigh - A modest expression, used both in scripture, as (Gen. 46:26, 1:5), and other authors.
To rot - Heb. to fall, that is, to die or waste away.
To swell - Suddenly and violently till it burst, which the Jews note was frequent in this case. And it was a clear evidence of the truth of their religion.
The L-rd make thee a curse - A usual form of imprecation (Isaiah 65:15, Jer. 29:22). Both because she had committed so heinous a fault, and forswore herself in denying the same.
The Israelites were accustomed, instead of formally repeating the words of an oath merely to say, "Amen," a "so be it" to the imprecations it contained. The reduplication of the word was designed as an evidence of the woman's innocence, and a willingness that G-d would do to her according to her desert.
Write these curses in a book - The imprecations, along with her name, were inscribed in some kind of record--on parchment, or more probably on a wooden tablet.
Blot them out with the bitter water - If she were innocent, they could be easily erased, and were perfectly harmless; but if guilty, she would experience the fatal effects of the water she had drunk. Shall wash the curses, which are written, into the water in the vessel.
Conceive seed - That is, shall bring forth children, as the Jews say, in case of her innocence, she infallibly did, yea though she was barren before.
This is the law of jealousies - Adultery discovered and proved was punished with death. But strongly suspected cases would occur, and this Law made provision for the conviction of the guilty person. It was, however, not a trial conducted according to the forms of judicial process, but an ordeal through which a suspected adulteress was made to go - the ceremony being of that terrifying nature, that, on the known principles of human nature, guilt or innocence could not fail to appear. From the earliest times, the jealousy of Eastern people has established ordeals for the detection and punishment of suspected unchastely in wives. The practice was deep-rooted as well as universal. And it has been thought, that the Israelites being strongly biased in favor of such usages, this law of jealousies "was incorporated among the other institutions of the Mosaic economy, in order to free it from the idolatrous rites which the heathens had blended with it." Viewed in this light, its sanction by divine authority in a corrected and improved form exhibits a proof at once of the wisdom and condescension of G-d.
Guiltless - Which he should not have been, if he had either indulged her in so great a wickedness, and not endeavored to bring her to repentance or punishment, or cherished suspicions in his breast, and thereupon proceeded to hate her or cast her off. Whereas now, whatsoever the consequence is, the husband shall not be censured for bringing such curses upon her, or for defaming her, if she appears to be innocent. Her iniquity - That is, the punishment of her iniquity, whether she was false to her husband, or by any light carriage gave him occasion to suspect her. The man might accuse his wife on suspicion and NOT be reproved.
Equal rights? I guess not!