In addition to the intrinsic value of the mitzva of ona, which gives expression to the love between husband and wife, the mitzva also serves as a shield against adultery. For this reason, unmarried people are more vulnerable to sexual temptation, and they must therefore strengthen themselves through Torah study and mitzva observance so that they save the power of their love for their true and holy match through the framework of marriage. Sometimes a person’s sex drive is so strong that it is extremely difficult to resist. In that case, the more one bolstered himself through Torah study and mitzva observance, the more he finds the strength to resist temptation.
The Talmud (Menaḥot 44a) recounts:
Natan said: There is no mitzva in the Torah, not even a minor one, whose reward is not enjoyed in this world. As for reward in the next world, who knows how great it will be! Go and learn this from the mitzva of tzitzit. A certain man was very meticulous in observing the mitzva of tzitzit. He heard about a prostitute, in one of the towns by the sea, who charged 400 gold coins as her wages. He sent her 400 gold coins, and arranged a time to meet. At the appointed time, he sat at the door. Her maidservant came and told her, “The man who sent you 400 gold coins has arrived and is waiting at the door.” She replied, “Let him in,” and he entered. She had set for him seven beds, six silver and one gold. Between each bed was a silver ladder, and the uppermost was of gold. She climbed up and sat naked on the topmost bed. He, too, started to climb up in order to be naked with her. While he was climbing up, his four tzitziyot hit him in the face. He climbed down and sat on the ground. Then she, too, climbed down and sat on the ground. She exclaimed, “By Rome! I will not let you go until you tell me what flaw you saw in me!” He responded, “By the Temple service! I have never seen a woman as beautiful as you. But the Lord our God has given us a mitzva called tzitzit, in the context of which it is twice written, ‘I am the Lord your God’ (Bambidbar 15:41). This means ‘I am the One Who will exact punishment in the future, and I am the One Who will give reward in the future.’ At this moment, these fringes appeared to me as four witnesses [testifying against me].” She said to him, “I will not let you go until you tell me what your name is, what city you are from, who your rabbi is, and the name of the beit midrash in which you study Torah.” He wrote it down and gave it to her. She immediately divided all her property into three parts: one third she gave to the government (so that they would permit her to convert to Judaism), one third to the poor (to atone for her sins), and one third she kept for herself, as well as the bedspreads. She then went to R. Ḥiya’s beit midrash. She said to him, “Rabbi, tell me what I must do to convert to Judaism.” He replied, “My child, perhaps you have your eyes set on one of the students?” [He was concerned that she wanted to marry one of the students because she could not find a husband among her own people, or because she wanted his money, but did not really want to convert for the sake of heaven.] She took out the note and handed it to him. [The note contained the specifics of the incident, which demonstrated that she was both wealthy and desired by many, but that she chose this student because of his greatness of spirit. R. Ḥiya therefore agreed to convert her.] He said to her, “Go and collect what you acquired.” The same bedding that she spread out for him sinfully, she now spread out for him lawfully. This is the reward for a mitzva in this world. As for the next world, who knows how great it will be!
Therefore, we see that when the sex drive spills over into licentiousness, it is wicked. But when it is expressed within the framework of a proper marriage, it is good and holy, and is even considered a heavenly reward.