"…In the business world a handshake is considered the standard greeting for both men and women. Since one is not allowed to touch a woman as an expression of affection, a question arises if shaking hands with a woman in a business situation is permitted. Horav Moshe Feinstein zt”l maintains it is difficult to say that shaking hands is not considered an expression of affection. In another teshuva he wrote that doing so is forbidden. This is also the opinion of many other poskim. This issur still applies even if by refraining from shaking hands one will cause the woman to be embarrassed. Some poskim say it is better to be killed than to shake the hand of a woman.…"
Yeshiva World has a long article about kol isha (the prohibition against hearing a woman sing), shaking hands with a woman and related prohibitions, written by Rabbi Moishe Dovid Lebovits of KOF-K Kosher Supervision.
All of these are rabbinic prohabitions, and they give outsiders a good look into how rabbis viewed (and still view) women and sex.
As you read this, keep in mind that ervah means nudity or nakedness of a part of the body that is kept covered for modesty reasons:
…Kol Isha - The Voice of a Woman
The Gemorah in Berochos[4] says that the voice of a [married] woman is an ervah,[5] since it may bring a person to certain desires.[6] According to many poskim this issur is d’rabanan in nature,[7] and often applies to one’s wife as well.[8] One is not allowed to hear the voice of a woman while she is singing[9] even without specific intent to enjoy her voice. A woman’s non-singing voice is permitted to be heard[10] as long as one is not listening with specific intent to enjoy her voice.[11]
Krias Shema
There is a machlokes haposkim if the issur of kol isha still applies when one is saying krias shema, or other devarim shebekedusha. Although some say that this din does not apply while saying krias shema etc,[12] most poskim disagree with this and forbid hearing kol isha while reciting krias shema or any other devar shebekedusha.[13] One who read krias shema while listening to a woman sing must repeat it without the accompanying berochos.[14]
Learning Torah
One should not learn Torah out loud where one can hear kol isha.[15]
Single Girls
Many poskim say one is also forbidden to hear the singing voice of a single girl.[16] There is a discussion in the poskim as to what age this issur begins. Some poskim say the age starts from three,[17] others say it starts at six,[18] and others say the issur begins at nine years old.[19] Horav Moshe Feinstein zt”l[20] says in a pressing situation one can be lenient until the age of eleven.[21]
A sister-in-law may not sing in front of her brother-in-law once she is six or seven years old.[22] A girl may sing in front of her father, grandfather, son or grandson.
Even when one is permitted to listen to single girls singing, one must not have in mind to enjoy it.[23]
A Non-Jewish Woman
A non-Jewish woman’s singing voice is forbidden regardless of her age[24] or attractiveness.[25]
Parents Attending Daughters Choir
Parents may attend their daughter’s choir until she has reached the age of eleven.[26]
Sisters
There is a discussion in the poskim if the issur applies to a sister. Some poskim hold that the issur applies to a sister just like it does to any other woman.[27] Other poskim say that the issur for a sister begins when she is eleven.[28] Although the custom in many places is to permit kol isha in regard to a sister,[29] one who is stringent is praiseworthy.[30]
Mothers
Some poskim are stringent and do not permit one to hear his mother sing while saying krias shema or learning,[31] while others are lenient.[32]
Family Singing- Shabbos Zemiros and the Haggadah
Many times one wishes to sing zemiros or the haggadah[33] with his wife and daughters and the question arises as to how doing so is permitted since one is not allowed to say holy words while hearing his wife etc singing. Many poskim are indeed stringent and forbid singing with one’s wife and daughters.[34]However, some poskim permit singing zemiros even while his wife is singing as well[35] (as long as there are no guests at the table for whom his wife’s voice would be an ervah).[36] According to the stringent view, if the women insist on singing the men should sing much louder to drown out the voices of the women.
One who is sitting at a family Shabbos table with guests who are not direct family members may not sing together with his wife etc. Although some say doing so is permitted since the voices are hard to hear individually,[37] one should not rely on this opinion.[38]
Musical Instruments
The issur of kol isha does not apply to hearing a woman playing a musical instrument.[39]
Woman Lecturing
There is a discussion in the poskim if a man may hear a woman lecturing.[40]
Storytelling
A man may hear a woman tell a story even if she is telling it with a little emotion etc. Some say if the woman is using hand motions, etc then a man should refrain from listening to the story,[41] while others feel that even if “she gets into it” it is still permitted for a man to listen to the story.[42]
Bedtime
If a woman sings to her child at bedtime etc the husband should be careful not to be learning or saying a davar shebekedusha at that time.[43]
Woman Singing on the Radio
Some say the issur of kol isha only applies where one recognizes the woman who is singing, or at least can see her. However, where one does not recognize the woman who is singing and does not see her then it is permitted to listen to her singing. According to these poskim one may listen to a woman singing on the radio if he does not know the woman.[44] However, this opinion should not be relied upon for halacha l’maseh since most poskim do not agree with it.[45] Even according to those who are lenient it is not a refined thing to do.[46] Others say if the singing is not live (i.e. it is on tape, CD etc.) it is permitted since it is her actual voice (live radio) that is forbidden.[47] It must be noted that even those who permit listening to recorded singing only permit it if one heard it while making a beracha, but listening to it l’chatchilah is always forbidden.[48]
Humming / Whistling
Humming[49] and whistling are like singing and are included in the issur of kol isha.[50]
Girls Singing Where Men Pass by etc.
According to some poskim girls davening in a school should try to refrain from singing loud enough to be heard by men passing by outside.[51] The same is true for girls who go on a trip with a Jewish male driver;[52] for a playschool teacher working at home whose singing will be heard by her husband who is learning;[53] and a woman in a bungalow colony who is singing in her bungalow. In these situations men who pass by should distance themselves from the singing. Where this is not practical, the woman should either lower her voice or refrain from singing until the men have left the area.[54]
Women hearing Women
A woman is allowed to hear another woman sing and it is not considered an ervah.[55]
On the Road
One who finds himself on the road where he is not able to avoid hearing a woman singing may recite krias shema or read other sacred texts while hearing women singing.[56] If possible, it is preferable to avoid doing so by covering his ears etc.[57] For example; this situation would apply when one is in a hotel lobby with a radio playing.
Choir
A woman should not accept a job as a choir leader if the choir will perform in front of men.[58]
Opera
Similarly, a man may not go to an opera where women will be singing.[59]
Morah
A Morah of children who have reached the age of chinuch can sing pesukim in front of her class.[60]
Hearing Music in a Cab
Many times one who is driving in a cab hears non-Jewish music being sung by women on the radio. The question arises if one is permitted to continue his car ride while listening to such music. L’chatchilah, one should ask the driver to turn off the music.[61] If the driver refuses to turn off the music one can be lenient and continue the cab ride for a number of reasons. 1. One may rely on those poskim who maintain that one may hear singing of a woman who he does not recognize. 2. One may rely on those poskim who say that one may hear singing of a woman that he can not see. 3. One has in mind not to have enjoyment from her voice. 4. It is in a situation where he can not refrain from the music.
Handshaking
A handshake is a ritual in which two people grasp each others hands to demonstrate good will and possibly originated as a gesture that the hands hold no weapons. Al pi kabalah when one shakes someone else’s hand he brings achdus between them.
In the business world a handshake is considered the standard greeting for both men and women. Since one is not allowed to touch a woman as an expression of affection,[62] a question arises if shaking hands with a woman in a business situation is permitted.[63] Horav Moshe Feinstein zt”l[64] maintains it is difficult to say that shaking hands is not considered an expression of affection. In another teshuva he wrote that doing so is forbidden.[65] This is also the opinion of many other poskim.[66] This issur still applies even if by refraining from shaking hands one will cause the woman to be embarrassed.[67] Some poskim say it is better to be killed than to shake the hand of a woman.[68]
Many times in the business world one comes across a situation where he may have to shake the woman’s hand. There are a few solutions to avoid shaking a woman’s hand:
s One can explain to her that refraining from handshaking is not a personal thing but is for religious reasons, since Jewish men do not shake the hand of any women unless it is their own wife or mother.[69] Experience has shown that the secular world respects statements of religious conviction and adherance to Torah principles.[70]
s One can hold a business card in his hand and give it to the woman instead of shaking her hand.[71]
Accepting Change from a Woman
There is a discussion in the poskim if touching a woman for non-affection purposes is permitted or not. Some say doing so is forbidden,[72] while others permit it.[73]
This dispute is applicable when one wishes to accept change from a woman as is common when going shopping. The custom of many is to refrain from taking things from or handing things over to a woman when there is a concern of touching.[74] Other people are lenient and do take change from or give money to a woman cashier.[75] Even according to the lenient opinion one should have in mind not to enjoy any touching that may occur when taking the change, etc. from the woman.[76] It is praiseworthy for the change to be placed on the table instead of being passed from hand to hand.[77]
Haircut
A man is forbidden to take a haircut from a woman barber since there is a lot of touching which may cause bad thoughts.[78]
Benefiting From a Woman
A man is not allowed to benefit from the assistance of a woman who is not his wife or very close relative (i.e. mother).[79] This issur includes being served drinks, making his bed, or being washed on his face, feet and hands.[80] One whose wife is present may be served by a different woman.[81]
One who is a guest at someone’s house may be served drinks etc by his host’s wife, since it is being done as hachnosas orchim and not because of affection.[82]
The custom is to permit a maid to provide benefit for a man since this usually does not bring one to bad thoughts.[83]
An older person may have a woman assist him with things he can not do by himself due to his condition. This is permitted since he is weak and sick and will not come to bad thoughts about her.[84]
Assisting a Woman
One may not assist a woman (who is not his wife or close relative) with everyday personal needs, such as putting on her coat.[85] One is obviously permitted to help rescue a woman who is drowning etc.[86]
If you want to check the footnotes, you can see them on Yeshiva World.
[Hat Tip: Seymour.]
Kol Isha - The Voice of a Woman
The Gemorah in Berochos[4] says that the voice of a [married] woman is an ervah,[5] since it may bring a person to certain desires.[6] According to many poskim this issur is d’rabanan in nature,[7] and often applies to one’s wife as well.[8] One is not allowed to hear the voice of a woman while she is singing[9] even without specific intent to enjoy her voice. A woman’s non-singing voice is permitted to be heard[10] as long as one is not listening with specific intent to enjoy her voice.[11]
Krias Shema
There is a machlokeshaposkim if the issur of kol isha still applies when one is saying krias shema, or other devarim shebekedusha. Although some say that this din does not apply while saying krias shema etc,[12] most poskim disagree with this and forbid hearing kol isha while reciting krias shema or any other devar shebekedusha.[13] One who read krias shema while listening to a woman sing must repeat it without the accompanying berochos.[14]
Learning Torah
One should not learn Torah out loud where one can hear kol isha.[15]
Single Girls
Many poskim say one is also forbidden to hear the singing voice of a single girl.[16] There is a discussion in the poskim as to what age this issur begins. Some poskim say the age starts from three,[17] others say it starts at six,[18] and others say the issur begins at nine years old.[19] Horav Moshe Feinstein zt”l[20] says in a pressing situation one can be lenient until the age of eleven.[21]
A sister-in-law may not sing in front of her brother-in-law once she is six or seven years old.[22] A girl may sing in front of her father, grandfather, son or grandson.
Even when one is permitted to listen to single girls singing, one must not have in mind to enjoy it.[23]
A Non-Jewish Woman
A non-Jewish woman’s singing voice is forbidden regardless of her age[24] or attractiveness.[25]
Parents Attending Daughters Choir
Parents may attend their daughter’s choir until she has reached the age of eleven.[26]
Sisters
There is a discussion in the poskim if the issur applies to a sister. Some poskim hold that the issur applies to a sister just like it does to any other woman.[27] Other poskim say that the issur for a sister begins when she is eleven.[28] Although the custom in many places is to permit kol isha in regard to a sister,[29] one who is stringent is praiseworthy.[30]
Mothers
Some poskim are stringent and do not permit one to hear his mother sing while saying krias shema or learning,[31] while others are lenient.[32]
Family Singing- Shabbos Zemiros and the Haggadah
Many times one wishes to sing zemiros or the haggadah[33] with his wife and daughters and the question arises as to how doing so is permitted since one is not allowed to say holy words while hearing his wife etc singing. Many poskim are indeed stringent and forbid singing with one’s wife and daughters.[34]However, some poskim permit singing zemiros even while his wife is singing as well[35] (as long as there are no guests at the table for whom his wife’s voice would be an ervah).[36] According to the stringent view, if the women insist on singing the men should sing much louder to drown out the voices of the women.
One who is sitting at a family Shabbos table with guests who are not direct family members may not sing together with his wife etc. Although some say doing so is permitted since the voices are hard to hear individually,[37] one should not rely on this opinion.[38]
Musical Instruments
The issur of kol isha does not apply to hearing a woman playing a musical instrument.[39]
Woman Lecturing
There is a discussion in the poskim if a man may hear a woman lecturing.[40]
Storytelling
A man may hear a woman tell a story even if she is telling it with a little emotion etc. Some say if the woman is using hand motions, etc then a man should refrain from listening to the story,[41] while others feel that even if “she gets into it” it is still permitted for a man to listen to the story.[42]
Bedtime
If a woman sings to her child at bedtime etc the husband should be careful not to be learning or saying a davar shebekedusha at that time.[43]
Woman Singing on the Radio
Some say the issur of kol isha only applies where one recognizes the woman who is singing, or at least can see her. However, where one does not recognize the woman who is singing and does not see her then it is permitted to listen to her singing. According to these poskim one may listen to a woman singing on the radio if he does not know the woman.[44] However, this opinion should not be relied upon for halacha l’maseh since most poskim do not agree with it.[45] Even according to those who are lenient it is not a refined thing to do.[46] Others say if the singing is not live (i.e. it is on tape, CD etc.) it is permitted since it is her actual voice (live radio) that is forbidden.[47] It must be noted that even those who permit listening to recorded singing only permit it if one heard it while making a beracha, but listening to it l’chatchilah is always forbidden.[48]
Humming / Whistling
Humming[49] and whistling are like singing and are included in the issur of kol isha.[50]
Girls Singing Where Men Pass by etc.
According to some poskim girls davening in a school should try to refrain from singing loud enough to be heard by men passing by outside.[51] The same is true for girls who go on a trip with a Jewish male driver;[52] for a playschool teacher working at home whose singing