The obligation of ona is incumbent upon the man, as the verse states, “He shall not withhold she’erah, kesutah, or onatah” (Shemot 21:10). Ramban explains that she’erah refers to flesh-to-flesh contact during intimacy, kesutah refers to the bed and bedding used by the couple during intimacy, and onatah as referring to the conjugal act itself (Ketubot 48a; see above, 1:3). If a husband does not fulfill this mitzva and thereby causes his wife pain, he is in violation of a Torah prohibition (above, 1:2). Of course, if she does not respond joyfully to her husband, the mitzva is worthless; thus, fulfillment of the mitzva depends on both of them. Nevertheless, the primary duty is the man’s, just as the mitzva to marry is incumbent upon the man, making him responsible to court his future spouse, gain her consent to marry, and then marry her.
To understand the difference between men and women, it must be made clear that if a man does not verbally articulate his love for his wife and does not increase her pleasure by embracing and caressing her while gradually advancing toward her erogenous zones, it stands to reason that he will not manage to make her climax. One of the wonderful characteristics of women is that spirit, mind, and body are more integrated in them than they are in men. Therefore, under normal circumstances, it is only when all of these elements are brought together in love and pleasure that a woman can reach orgasm. This process is complex and takes time.
In contrast, it is the nature of men to bifurcate different realms. A man can satisfy his physical lust even without an emotional or spiritual connection. This trait can be very valuable when he needs to ignore everything going on around him and focus his energy on a single goal. It is what enables a young man to energetically court his future wife, overcome obstacles, and persist until she agrees to marry him. This is also why it is the man who performs the act of kiddushin that effects their marriage. This trait is also valuable for a soldier in battle.
On the other hand, after achieving his goal of getting married, men can sometimes lose interest in having a wholesome emotional relationship. They were so focused on getting married that they neglected to properly prepare themselves for all the challenges of married life. Because of this, a new husband is commanded not to serve in the army or take business trips during his first year of marriage, as the verse states: “He shall be exempt one year for the sake of his household, to give happiness to the woman he has married” (Devarim 24:5). This allows newlyweds to build a strong foundation for their married life.
Something similar can happen during the buildup to sexual relations. A man might be very passionate beforehand, but as soon as he ejaculates, he is liable to lose interest in his wife. And since men are physiologically capable of reaching the climax of physical pleasure within minutes, without providing their wives with any joy – the mitzva of ona is incumbent upon the man, and its primary element is to bring as much joy and pleasure to his wife as he can. The Sages thus caution: “A husband may not compel his wife to fulfill the mitzva…. Any man who compels his wife to perform this mitzva will have indecent children” (Eruvin 100b).
Thus, even though marital sexual relations are a mitzva, if their purpose is to satisfy only the man’s urges, without him trying to bring his wife pleasure, there is no mitzva. Thus, because of women’s nature, the husband has to make sure to express his love for his wife. This will give their sexual union greater depth and wholesomeness.
Conversely, when a woman does not desire to be intimate with her husband, is not responsive to his advances, and does not experience joy with him, she actively countermands the mitzva. The mitzva is to bring her joy, so when she is not happy, the mitzva is completely undermined. If this situation persists, she will destroy their home. As we learned, if a woman claims that she finds her husband repulsive, he must divorce her, but she forfeits her ketuba (Ketubot 63b). He must divorce her because it is impossible to maintain a marriage without the joy of sexual relations, but she forfeits her ketuba because she breached the most basic essence of marriage.
Likewise, when a man does not keep to the frequency required of him, or when he is not willing to please his wife in the accepted ways – for example, if he is not willing to have sexual relations unless he is clothed – the woman can sue for divorce, and her husband is obligated to divorce her and pay the ketuba in full (SA EH 76:13).