The Torah in Parshat Acharei Mot outlines the different types of forbidden sexual relationships, some of which are mentioned in the pesukim below.
ו. אִישׁ אִישׁ אֶל כָּל שְׁאֵר בְּשָׂרוֹ לֹא תִקְרְבוּ לְגַלּוֹת עֶרְוָה…:
יט. וְאֶל אִשָּׁה בְּנִדַּת טֻמְאָתָהּ לֹא תִקְרַב לְגַלּוֹת עֶרְוָתָהּ:
כ. וְאֶל אֵשֶׁת עֲמִיתְךָ לֹא תִתֵּן שְׁכָבְתְּךָ לְזָרַע לְטָמְאָה בָהּ:
- A man should not draw close to reveal nakedness…
- Do not draw close to a woman while she is in her nidda impurity, to reveal her nakedness.
- You shall not lie carnally with your neighbor’s wife to make yourself impure with her.
The Torah first describes relationships that are prohibited due to a familial connection (in pesukim 7–18), then lists the prohibition of having relations with a nidda (pasuk 19), and finally mentions the prohibition of eishet ish – a married woman (pasuk 20).
There is much to learn from the juxtaposition of these different categories as well as the language which the Torah uses to describe these prohibitions. From the words “lo tikrevu,” literally “do not draw close,” one may infer that any type of intimacy regarding these people is forbidden from the Torah. However, the phrase “l’galot erva,” “to reveal nakedness,” implies that the prohibition is limited to the sexual act of intercourse.
The Midrash relates that the Sages discuss this exact question.
I only know that the actual act of revealing is prohibited. From where do I know that drawing close is also prohibited? Therefore, the Torah adds, “do not draw close.” But the Torah uses both phrases “to draw close” and “revealing” only with regard to a nidda. From where do I know that this applies to all forbidden relationships? Therefore, the Torah states, “do not draw close to reveal…”
The Midrash states that even drawing close without the accompanying sexual act is prohibited, both with regard to a nidda as well as with regard to other married women. However, further clarification is needed as to whether the Midrash is explaining the peshuto shel mikra, the literal understanding of the words (i.e., that this is a Torah prohibition), or whether this prohibition is rabbinic in nature and the Midrash utilizes the verse as an asmachta – support for a rabbinical decree.
This question is disputed by the Rishonim. The Rambam writes:
One must not draw close to someone forbidden to you in manners that lead to revealing the intimacy – such as hugging or kissing and hinting or jumping, as the verse states regarding familial relations: “Do not come close to reveal nakedness.” The Sages had a tradition that this is a warning not to draw close in any form that leads to revealing intimacy.
The Rambam understands that the Torah prohibited not just the sexual act, but any act that might lead to it, even if one ultimately does not perform the sexual act. One can postulate that the reason for the prohibition is either that the Torah itself made some type of gezeira lest one come to commit a sexual act, or that the Torah sees this type of intimacy or flirting as unacceptable in and of itself, and one must distance oneself from any type of sexual pleasure from a prohibited relationship.
The Ramban, on the other hand, has a very different approach. He writes:
One should know that when the Torah describes “drawing close,” it is referring to the physical act of intercourse as the verse states, “I came close to her but did not find her to be a virgin.”
According to the Ramban, the Torah only prohibited the sexual act of intimacy, and the usage of both the terms kirva and l’galot erva is not indicative of an independent prohibition. Furthermore, the Ramban did not view the Midrash as contradicting his position. Rather, he explains the Midrash in the following manner:
Perhaps what they are stating (in the Midrash) is that the Torah made a fence for its own rules and used the word kirva and erva in order that the Sages could institute a fence using the Torah’s own language so that people would listen.
The Ramban holds that although the prohibition is rabbinic in nature and the verse is an asmachta, the Torah purposely chose this language to enable Chazal to make a decree using the force of the Torah’s own language. The Ramban suggests that the Torah frowns upon such behavior but is insistent that this is not a formal biblical prohibition.
Thus, the Rambam and Ramban both agree that a prohibition of drawing close to forbidden arayot exists; they disagree as to whether this is a Torah violation or only a rabbinic decree that dovetails with the intention and desire of the Torah. Most Rishonim agree with the Rambam, and this is the way that the Shulchan Aruch rules as well.
Derech Chiba – A Manner of Affection
We have seen so far that Rishonim disagree as to whether physical closeness with forbidden relationships is a Torah or rabbinic prohibition. According to both sides, we must still analyze what type of closeness is prohibited.
One could posit that according to the Rambam, the Torah prohibited any type of physical closeness even where no sexual connotation or innuendo is apparent (such as shaking hands). According to this approach, it would seem that almost every scenario involving physical contact would be forbidden. Alternatively, the Rambam may agree that the Torah only prohibits closeness with some sexual connotation.
The Beit Shmuel interprets the Rambam in line with the first approach that the Torah prohibits any physical contact mide’oraita. He opines that although the Ramban disagrees with the Rambam, he agrees that this is indeed the Rambam’s opinion. The Beit Yosef also appears to understand the Rambam this way, since he posits that according to the Rambam, it would be prohibited for a husband to measure the pulse of one’s wife who is a nidda (even though measuring a pulse is not an affectionate activity), as the nature of the prohibition is still de’oraita.
The Shach, on the other hand, explains the Rambam according to the second approach – namely, that there is only a Torah violation with a sexual connotation. The Igrot Moshe explains that the Beit Yosef holds this way as well. Although the Beit Yosef prohibits taking the pulse of one’s wife who is a nidda according to the Rambam, and it is reasonable to assume that this does not qualify as an act with sexual connotation, this halacha applies specifically to a husband and wife, since they are accustomed to being intimate with one another. However, non-intimate physical contact between a male and female is permitted according to the Torah in other cases.
The simple reading of the Rambam in Hilchot Issurei Bi’ah (21:1) seems to follow the second approach, as the Rambam states explicitly that the prohibition of physical intimacy such as hugging and kissing applies only “derech ta’ava v’neheneh b’kiruv basar,” “in a manner of desire and deriving pleasure from the physical intimacy.” In fact, these words are quite difficult for the Beit Shmuel to explain, as he holds that the Rambam biblically prohibits any closeness, even if is not derech ta’ava. The Beit Shmuel resolves this difficulty by explaining that the correct reading of the Rambam is “a manner of desire or by deriving pleasure” (meaning that the vav of v’neheneh means “or” as opposed to “and”).
However, the Rambam later in the same chapter highlights that touching a relative is prohibited rabbinically even when contact with that relative is not considered derech ta’ava (such as with a brother and sister), which seems difficult for the Beit Shmuel.
It seems that according to the Beit Shmuel, the general prohibition only applies to individuals to which one has a natural sexual attraction. Regarding such people, any physical contact is prohibited from the Torah even if it is not derech ta’ava. Thus, the Beit Shmuel stresses that there is “pleasure from the closeness of the flesh.” This would not pertain to a brother and sister, where we assume that there is no pleasure involved.
The Ramban does not appear to distinguish between whether the closeness is derech ta’ava or not, and any type of closeness would be forbidden. Yet, the Ramban holds that closeness of any sort violates a rabbinic prohibition only. Hence, there would be no practical difference between the opinion of the Ramban and the Shach’s understanding of the Rambam in cases of closeness without sexual intent. According to both, this would constitute a rabbinic prohibition.
When trying to define what is considered a closeness that has sexual tendencies, one can suggest two possible definitions. It can either be dependent on the intention of a person – whether a person intends to derive sexual pleasure from this contact; or whether one actually derives some type of sexual pleasure in reality.
A practical ramification of these two definitions would be regarding shaking hands as an act of courtesy. According to the first definition, this would be allowed, as there is no intention to derive sexual pleasure, whereas according to the second definition, if in fact one does derive pleasure, it would be biblically prohibited (according to the Rambam).
This question of whether closeness with sexual tendencies is defined by intent or actual pleasure may be a machloket Rishonim. The Rambam writes (in Issurei Bi’ah 21:6) that “even though there is no desire or pleasure at all,” it is still considered inappropriate to engage in physical contact with arayot for which one has no physical attraction (such as one’s sister). This may indicate that with regard to arayot to which one is attracted, if one does derive pleasure, even unintended, it is prohibited.
By contrast, Rabbeinu Yona writes that “a person shall not come close to forbidden relations… for such a closeness includes touching her hands or face or any other limb in order to get pleasure from it.” Rabbeinu Yona here seems to stress that the prohibition is focused on the intent to derive pleasure. This is the approach of the Meiri as well.
The Acharonim also seem to disagree about this issue of physical contact between men and women that does not involve deriving pleasure. The Ben Ish Chai notes the minhag in Bagdad for both men and women to kiss the hand of the Chacham. He defends this minhag by saying that it is “lichvoda shel Torah” and the intention is l’shem shamayim with no sexual connotation. Rav Ovadia Yosef, on the other hand, prohibits this, notwithstanding the above intentions. Rav Shlomo Amar also discusses this topic in his responsa Shama Shlomo and is lenient regarding certain relatives under specific conditions.
We have explored the machloket Rishonim as to whether closeness to an erva is a Torah or rabbinic violation. We also examined whether the prohibition focuses on one’s intention or the actual pleasure derived. May Hakadosh Baruch Hu guide his nation in the ways of kedusha and guard us from stumbling in this matter.
 Vayikra 18
Sifra, Parshat Acharei Mot
 Rambam, Minyan HaMitzvot HaKatzar, Negative Mitzva 353; see also Hilchot Issurei Bi’ah, ch. 21
 The Igrot Moshe, E.H. 4:60, holds that there is a Torah violation even if there is no physical contact, as the Rambam specifies “hinting or jumping.” However, this is difficult to understand, as the Rambam specifically states that the punishment for violation of this sin is rabbinic lashes, which implies that the prohibition is only rabbinic. This seems to be the understanding of the Maggid Mishneh as well. The Igrot Moshe argues that the reason the Rambam delineated the punishment as makkat mardut is because the prohibition of “kalut rosh” is a lav she’ein bo ma’aseh; hence, there are no lashes from the Torah, but the prohibition is still a Torah prohibition.
 See Rav Yosef Engel, Lekach Tov, Klal 8, who develops this idea in detail.
 Hasagot of the Ramban on Sefer HaMitzvot, Lo Ta’aseh 353
 Devarim 22:14
 See Shabbat 13a, where the Gemara brings differing Amoraic opinions regarding the permissibility of a man sleeping with his wife who is a nidda in the same bed when both are clothed. The Rambam and Ramban each interpret this Gemara in line with their overall approach. See Megilat Esther 353, who explains the Rambam’s interpretation of this Gemara. On the other hand, the Ramban quotes this sugya explicitly as a proof for his explanation.
 This position is taken by Meiri, Sanhedrin 66b, Rashi and Ritva to Shabbat 13b, Semag 126, and Chinuch 188, among others.
 Shulchan Aruch, E.H. 20:1 and 21:1
 Beit Shmuel, E.H. 20:1
 Responsa of the Rashba, HaMeyuchasot L’Ramban 127
 Beit Yosef, Y.D. 195
 Shach, Y.D. 195:20 and 157:10
 Igrot Moshe, loc. cit.
 Ramabm, Hilchot Issurei Bi’ah 21:6
 Regarding a father and daughter or mother and son, the Rambam explicitly states that physical contact with them is entirely permitted. Consequently, the issue raised here is not relevant in those cases.
 Rabbeinu Yona, Iggeret HaTeshuva
 Meiri, Avoda Zara 17
 Od Yosef Chai, Parshat Shoftim, 22
 See Kiddushin 81b and Tosafot there; Mordechai, Ketubot, siman 182; see also Shabbat 13a.
 Halichot Olam, vol. 8, p. 331
 Shama Shlomo, E.H. 2:12. See also Responsa Igrot Moshe (E.H. 1:56) who acknowledges that some are lenient though he does not think that one should practically rely on this; Responsa Bnei Banim (1:31), who is lenient, as well as others, including Rav Joseph B. Soloveitchik, who are lenient mentioned in www.ou.org/torah/files/r-manning-may-30-2018.pdf and www.torahmusings.com/2005/07/shaking-hands-with-women.