Siman 23

A person created in the image of God should understand and contemplate with his knowledge and intellect that the desire created within man was not created for the sake of desire, for it is contrary to the intellect, as the Sages, of blessed memory, expounded: "For He spoke, and it was" (Psalms 33:9) – this is a woman; "He commanded, and it stood" – these are children. A woman is a vessel full of filth and her mouth is full of blood, yet everyone runs after her [Shabbat 152a]. It was created only for the sake of procreation, which is the preservation of the world. This is why the Holy One, Blessed be He, said to strengthen this desire over human beings, and it was so, because He commanded His world to stand, as "He did not create it for void, He formed it to be inhabited." Were it not for the Holy One, Blessed be He, strengthening this desire in man, no person would attend to this because of the repulsiveness. And the proof for this—that it is not for any desire—is that immediately upon the emission of the seed, the desire is completely cut off, and every person will return to his heart and ask: where then is my desire that I craved just a moment ago? Rather, he should understand that after the seed has gone out to sow, there is no longer a need for it. Therefore, in the elderly who are not fit to emit seed, their desire ceases, which is not the case with the desires for eating and drinking, for even the oldest person desires somewhat to eat and drink. Therefore, a holy obligation is incumbent upon a person to guard his seed so that it does not go in vain, Heaven forbid, for it is holy. And the scientists have already found by means of a magnifying glass that in a drop of seed there is the entire form of a person, and one who emits it in vain is as if he kills a soul, Heaven forbid.

Therefore, our sages, of blessed memory, were very, very stringent regarding wasting seed, and this transgression is more severe than all the prohibitions in the Torah. And all the more so those who commit adultery with the hand and emit seed—it is not enough for them that it is a great prohibition, but rather one who does this sits in excommunication. Regarding this it is said, "Your hands are full of blood" (Isaiah 1:15), and it is as if he killed a soul. So too, one who intentionally causes himself an erection is in excommunication. Therefore, one should be very careful not to contemplate this, for contemplation leads to emitting seed in vain.

It is forbidden for a person to cause himself an erection intentionally or to bring himself to sinful thoughts; rather, if a thought comes to him, he should divert his heart from words of vanity to words of Torah, which is a "lovely hind and a graceful doe" and nullifies evil thoughts. Therefore, it is forbidden for a person to sleep on his back with his face upward, but rather he should incline slightly on his side so that he does not come to an erection, for when he sleeps on his back the spinal cord—through which the seed passes and whose source is from the brain—becomes heated. And he shall not look at domestic animals, wild beasts, or birds when they are mating with one another; however, those whose occupation is such, like those who mate domestic animals, are permitted even to insert them like a tube-applicator into a tube because they are occupied with their work and will not come to sinful thoughts.

It is forbidden for a man who is not married to place his hand upon his genitals so that he does not come to sinful thoughts, and even below his navel he should not place his hand lest he come to sinful thoughts. And if he urinated water, he should not hold the amah and urinate, but if he was married it is permitted when his wife is with him and she is pure, and some say that even if his wife is not with him it is permitted, and the opinion of the Tur is that even a married man is only permitted to hold from the atarah and below toward the ground, and in any case, whether married or not married, he should not extend his hand to the amah at all except at the time he needs to relieve himself. And to wash the amah together with the whole body is permitted when he washes in a passing manner, but to linger a long time in washing the organ is not proper to do so for perhaps he will become heated, and also when he washes he should not look at his nakedness and it is disgraceful, and all the more so that he should not look at the nakedness of his fellow. And likewise the sages, of blessed memory, forbade riding on an animal without a saddle so that the organ does not become heated from the flesh of the animal.

When one engages in relations with his wife, he should not be "threshing within and winnowing without" and emitting his seed in vain, and this was the act of Er and Onan whom Hashem put to death because they wasted their seed on the ground, as is written in the Torah of Moses. Therefore, a woman who has an obstruction in the womb and through this, when her husband engages in relations with her, he winnows without – it is forbidden, and it is seen that she should be healed from this or he should divorce her. However, it is permitted to engage in relations with a minor or an aylonit since he engages in relations in the manner of all the earth, and specifically when he has already fulfilled "be fruitful and multiply" or if he has another wife in places where it is permitted to marry two wives; but when he has not yet fulfilled "be fruitful and multiply" – he should not marry a minor who is not fit to give birth, and all the more so a sterile woman or an elderly woman. And know, that from the language of the Tur and the Shulchan Aruch in section 1, it implies that relations with a minor pertains to the prohibition of emitting seed in vain, and this requires great study and one must look into this.

A woman whom the doctors told that if she conceives she will die, and she is afraid to engage in relations in the usual manner because of the danger, regarding such a case our sages, of blessed memory, said [Yevamot 12b] that they may engage in relations with a moch. Rashi explained that she places a moch in the place of relations when they engage in relations so that they do not conceive. However, Rabbeinu Tam holds that this is a complete prohibition, for it is like one who casts his seed upon wood and stones; rather, he should engage in relations in the usual manner, and after the relations she shall place the moch to absorb the seed, for she is not commanded regarding the destruction of seed [and Rabbeinu Tam contradicts himself from Yevamot there to Ketubot 39a; and in the Shita Mekubetzet there it is written in the name of the Rosh, the Ramban, and the Ritva, and similarly in the Rashba in Yevamot and Ketubot there, and similarly the Mordechai at the beginning of Yevamot in the name of Rabbeinu Tam and the Rivan wrote that there is no prohibition to place a moch before relations, and also regarding placing it after relations the Rosh wrote there that there is no prohibition, and also the Ri in Tosafot Ketubot rejected his proof; therefore, when there is a danger that she will conceive, they may rely and permit it whether before relations or afterward, and it is explicitly implied so at the beginning of Niddah].

Our teacher, the Rema, wrote: In the Gemara, in the chapter "Kol HaYad," it is implied that it is forbidden to wear trousers if they are not made like leggings, because it leads to the destruction of seed. And even though it is possible to reject this, as in the Gemara it only says this regarding their days when they had terumah and there was a concern for bodily impurity, nevertheless, since the Rosh brought this in his rulings, it implies that even in this time it is forbidden. And as for the fact that they practiced permissively in the bathhouse, it is possible to say that for a brief time they did not forbid it. Thus far his words. And the matters are clear that this was only said regarding trousers made with a specific pocket for the organ by itself, for in this, heating is relevant. But in our trousers, what heating is relevant? And it is simple that in all generations they did not go without trousers [and so wrote the Pitchei Teshuvah in the name of the Atzei Arazim, and see Orach Chaim siman 91].

From his words it is implied that they would walk in the bathhouse in trousers, but this is not so in our time in our lands. Therefore, one must wonder why even many of the scholars and the God-fearing are not careful regarding a son going with his father to the bathhouse, or a son with his father-in-law, his mother’s husband, or his sister’s husband. For behold, this prohibition is explicit in the Gemara [Pesachim 51a] that it is forbidden to wash with his father, his father-in-law, his mother’s husband, and his sister’s husband. Our teacher, the Rema, writes the permission because they walk in trousers in the bathhouse, but in our time, what permission is there for this? And I thought to say that in the Gemara they said one should not "wash" with them, and standard washing in their times was in bathtubs, and in this it is forbidden that they should not sit in one bathtub, for in this there is hirhur; but in our bathhouse, where they are merely in one room, there is no concern in this. However, I saw in the Mordechai [ibid.] in the name of the Maharam of Rothenburg that this permission occurred to him and he rejected it from the perspective of logic, that there is no distinction in this. Nevertheless, the world perhaps relies on this; however, one who fears the word of Hashem should distance himself from this. And to wash with his primary teacher is also forbidden because of derech eretz; therefore, if his teacher needs him to serve him, it is permitted, as is written in Yoreh Deah siman 242. Likewise, if he was in the bathhouse before his teacher, he does not need to leave when his teacher arrives. But with his father, his father-in-law, his mother’s husband, and his sister’s husband, where the reason is because of hirhur—it is forbidden in every case. And so it is stated in the Gemara there, that in a place where it is not the custom for two brothers to wash as one because they are careful regarding this, two brothers should also not wash there as one; and the Rambam wrote likewise. But the Tur and the Shulchan Aruch did not write this because now this is not the custom in any place, and according to the law it is permitted, as is written in the Gemara there. And I am wondered at the Tur and the Beit Yosef that they did not mention this law at all, of the prohibition of washing with his father, etc., neither here nor in Yoreh Deah. And more than this, I am wondered at the Tur, that in the Kitzur Piskei HaRosh he also omitted it; see there. Only the Rambam and the Rema wrote them, and likewise the Rif and the Rosh, and it requires further study. And regarding going with a small son to the bathhouse—one should be in doubt whether it is permitted or not.

The early pious ones and the greatest of the sages—one of them boasted that he never looked at his milah, and among them were those who boasted that they never gazed at the form of their wife, because their heart turns away from words of vanity toward words of truth, which seize the hearts of the holy [Rambam].