The limits of kilayim keep:

• Individual creations true to themselves, in the way they were created by God, and
• Different, or opposing, spiritual forces governing creation in their own places and within their own bounds.

In the holiness of the Tabernacle or Temple, where opposites were peaceably and constructively resolved, kilayim in the form of sha'atnez was not only permitted but formed the foundation of all main tapestries and two of the High Priest's garments. Kilayim-type laws apply today to:

• Animals (not yoking an ox and donkey together; not interbreeding, say, a horse and a donkey to produce a mule),
• Food (not eating milk with meat),
• Clothing - not wearing a garment made of a mixture of linen and wool (sha'atnez), and
• Plants (interplanting, interbreeding, and grafting different species).
  Note Vineyards in Eretz Yisrael may only be near fruit trees if:
  1. A wall divides fruit tree and vineyard, OR
  2. The vineyard is not a bona fide vineyard. A bona fide vineyard has at least 5 grapevines in at least two rows, with at least two vines in one row and three in the other. 

Saying Baruch ha'mavdil bein kodesh l'chol after dark at the end of Rosh Hashana (as for Jewish festivals) does not affect the additions you will then say in birkat ha'mazon.

K'zayit is variously defined as being the volume of 1/3, ½, or 1 whole egg; 0.6 - 1.9 fl. oz. (18-56 ml), depending on the application.

• K'zayit for Seder Matza and Afikoman:  1.9 fl. oz. (56 ml) of matza.
• K'zayit for Bracha Achrona and Birkat HaMazon: 1.3 fl. oz. (39 ml, or 1/6 cup) of solid food.

Beitza, K'Beitza = 1.9 fl. oz. (56 ml); an egg size by definition.

 

1. What Makes a Woman a Nida

 
Introduction to What Makes a Woman a Nida
Vaginal Blood Flow
Only vaginal blood flow makes a woman nida. 
 
Nida D'Oraita
According to Torah law (d'oraita), a woman becomes a nida when she experiences a flow of uterine blood, preceded or accompanied by a hargasha. Because uterine blood flow is difficult to distinguish from the more general vaginal blood flow, we assume that a vaginal blood flow is from the uterus--unless a medical person (it could be a midwife) determines that the blood flow is not uterine.
 
Nida D'Rabanan
 
By rabbinic law (d'rabanan), a woman can become a nida even with only a qualifying stain (see below).

Hargasha
A hargasha is anything that signals that the woman's period is imminent. There are three classical hargashot, as well as possible hargashot that pertain only to an individual woman.
Note Many women today do not have hargashot.
 
Classical Hargashot
There are three classical hargashot:
1) Body Tremor
2) Petichat HaMakor
Some women, at petichat ha'makor (“opening of the uterus”), have a sensation of release similar to when one's bladder opens to urinate.
3) Zivat Davar Lach
Sensation of wet discharge that comes only with her period; this is not the wet discharge that every woman normally feels multiple times daily.
Note She does not necessarily need to feel it coming from her cervix in order for it to make her a nida.
 
Individual Hargashot
What Is an Individual Hargasha
The individual hargasha can be any physiological occurrence (pimples on her face, a bout of yawning, a bloated feeling in the belly, etc.) that correlates with a woman's getting her period within 24 hours. To become established as a hargasha, it must have happened three times in a row.
 
Note Cramps for most women may be a hargasha, since they may mean that the woman is about to have her period.
 
When a woman has a hargasha, we assume that her period has started, and she should immediately stop what she is doing and check internally with a bedika cloth. If she does a bedika as soon as possible and the cloth shows a forbidden color, or shows no discharge at all, she immediately becomes nida for at least 12 days, after which she goes to the mikva. 
Note If she had a hargasha and finds no blood and no discharge, she becomes a nida, since we assume there was blood and she just didn't find it.  If the bedika cloth shows brown, magenta, salmon, brick, amber, orange, etc., the rabbi will want to see the cloth to determine her status.
Note Most medium browns are OK.
 
What To Do If Not Sure
If she is not sure she has had a hargasha, she asks a rabbi and together they will sort out the answer.
 
 
Nida D'Rabanan
 
Stain (without Hargasha)
 
Stain Colors
A rabbi should be consulted in all matters of questionable colors of stains.  Some may seem to you to be forbidden but turn out to be permissible, and vice versa.
 
Stain Location
A stain of a color that could make a woman a nida can be on material or on the woman's body. None of the following lenient conditions apply if the woman is nida d'oraita:
   

1. Not positively attributable to another cause, AND
2. At least the size of a gris. For small, unconnected spots, she must evaluate whether, together, they equal the size of a gris (on material, the spots DO NOT get combined). If yes, she should consult a rabbi.

 
 
II. HARCHAKOT: How Do the Couple Conduct Themselves while the Wife is a Nida?
 
According to Torah law, when a woman is a nida, she and her husband are prohibited not only from having intercourse, but also (“lo tikrav”—Vayikra 18:19) from having any physical contact of a passionate or romantic nature (negiya shel chibuk v'nishuk)--those patterns of physical contact that often lead to intercourse. Since the penalty for violation is kareit, husband and wife should live separately during the nida period, but because we don't, we use “distancers” (harchakot) as reminders of distance while living together in the same home. The harchakot sensitize us to the smallest gestures of love. The couple who know that in a finite amount of time their union will not only be permitted, but even be davar sh'bekedusha--a thing of sanctity--will have the willpower to wait it out.
 
These harchakot are applied during the nida period:
                                 
III. Tahara after Nida:    

1. Wash or cleanse lower regions of the body.
2. Do an internal check/bedika: Insert a white cloth into vagina and circle it around to make sure to get every nook and cranny.
3. Moch dachuk: Insert a bedika cloth within two halachic hours of sunset and leave it in until after dark.

 

1. Bedika

 

2. White Underpants

 

3. No Hesech Da'at

A woman does not need to think about the seven clean days all of the time, but she must keep in mind, during the entire nida purification process, that she is not in an active nida state.  
Situation A woman found a stain and asked a rabbi about it. She assumed she was definitely nida.
What To Do Once she assumes that she has become a nida during that seven-day period, she must begin her count again--even once she has found out that she was not, in fact, a nida. 
Note If she asked the rabbi while not yet assuming that she was definitely a nida, she may continue her original count after the rabbi determines that she was not a nida.

• Full body cast.
• Being covered with sand.
• Being sweaty from head to toe.

• Moisturizer that covers most of her body.
• Adhesive that is left on her skin after a band-aid has been removed.
• Imperfect manicure, if she would not go to an interview like that.

         
 

• Shalom Bayit (in this case, she is not permitted see her husband until after dark Friday night).
• Dangerous Neighborhood.
• Infertility Issues (if she will miss ovulation if she does not go Friday night).

    Kosher immersion/tevila requires simultaneous immersion of every exposed part of the body (not bet ha'starim).   Here is the best way to accomplish simultaneous immersion:

• Enter the water until it is about 12 inches above the navel. 
• Make sure that every part of your body is relaxed (if you squeeze anything, you create crevices and cracks that impede complete access to your skin). 
• “Flesh”/basar is exposed to the water when standing while leaning a little forward.
• Exhale and push yourself under the water until you are certain that all of your body and all of your hair are submerged. 
• Once your head is above the surface of the water, say the blessing and then immerse again, the same way.

 
IV. Anticipating the Next Period/Veset
 
What To Anticipate
In anticipating the time of the month when her period is most likely to occur (onat ha'veset), a woman must determine both:

1. The day of the month, and
2. Whether it will begin during the daytime period (sunrise to sunset) or the nighttime period (from sunset to sunrise)

 
Regular and Irregular
Every woman needs to be able to anticipate her next period, whether she is a) regular or b) irregular. “Regular” is determined by any pattern to one's menstrual cycle that occurs three times in a row.
Note It is very uncommon for a woman to maintain her regular period for a long time.
 
Anticipating a Regular Period
Here are the five most classic regular patterns:

1. Veset HaChodesh (Monthly Cycle)

   

2. Veset Haflaga (Intervals Cycle)

 

3. Veset HaGuf (Body Symptoms Cycle)

 

4. Veset HaMurkav (Combination Cycle)

    A woman with an irregular period may have to abstain from relations and affectionate intimate contact (negiya shel chibuk v'nishuk) during these three onot/time periods:

1. Yom HaChodesh

 

2. Haflaga

 

3. Ona Beinonit

Jewish Festivals are listed in the Torah and are of two types: 

1. Three pilgrimage festivals (shalosh regalim):

• Passover,
• Shavuot, and
• Sukkot (including Shimini Atzeret).

These festivals were celebrated in ancient times by "appearing before God"--by bringing offerings to the Tabernacle or Temple.

2. High Holidays: 

• The Jewish New Year (Rosh Hashana—“Yom Teru'a” in the Torah), and the
• Day of Atonement (Yom Kippur).

 
Duration
Jewish holidays that were originally one day are now observed as follows:

• Rosh Hashana--2 days.
• Yom Kippur--1 day.
• Shavuot--1 day in Eretz Yisrael or 2 days elsewhere.
• Passover has festival days at the beginning and end of the holiday and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Passover lasts for 7 days in total and the first and last days are festival days. Outside of Eretz Yisrael, Passover lasts 8 days and has two festival days at the beginning and two at the end.
• Sukkot has festival days at the beginning and at the end and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Sukkot lasts for 8 days and the first and last days are festival days (the last day is Shimini Atzeret). Outside of Eretz Yisrael, Sukkot lasts for 9 days and the first two days and last days are festival days (the 8th day is Shimini Atzeret and the 9th day is Simchat Torah).

Character
Each holiday contributes its own character to Jewish life (Passover--the theme of freedom; Yom Kippur brings atonement, etc.). 

Celebrating
How to celebrate these holidays is detailed in our Oral Law and halacha books. Jewish festivals as practiced today are similar in holiness to Shabbat. As with Shabbat, the Jewish festival has candle lighting, kiddush at two meals, and havdala.   We eat our best food and wear our best clothing on Jewish festivals (we eat our next-best food and wear our next-best clothing on Shabbat!).
The main idea behind eating meals on Jewish festivals is joy (simcha), so you should drink wine and eat meat (only if you enjoy wine and meat).  There is no third meal on Jewish festivals since people used to eat two meals each day (adding a third meal on Shabbat was for enjoyment/oneg).
 
Melachot
Any activities or actions permitted on Shabbat are also permitted on the Jewish festivals. Actions that are forbidden on Shabbat are generally also forbidden on Jewish festivals, but there are some leniencies (only if the actions are needed for that festival day).
Examples

• Lighting from an existing flame,
• Cooking and baking for the Jewish festival day, and
• Carrying outside the eruv (hotza'a--transferring objects between domains).

 
Grama
Grama (indirectly causing an action) is permitted on Jewish festivals (but not on Shabbat). For example, you may advance or delay a timer that will make a light go on or off in the future (the timer must already be plugged in and operating from before sunset of the festival day).
Note For an action to be considered indirect based on time, there must be at least 2.5 seconds after the first action is done before the resulting action begins to happen.

Psik Reisha Dla Neicha Lei
Psik reisha dla neicha lei is forbidden on Jewish festivals, just as it is on Shabbat.

D'oraita Restrictions
D'oraita restrictions apply world-wide to:

• First and seventh days of Passover,
• First and eighth days of Sukkot,
• First day of Shavuot,
• Yom Kippur,
• First day of Rosh Hashana.

Note The same restrictions apply to all other Jewish festival days but are rabbinical.
 
Women
In general, women are not required to perform the positive, time-dependent commandments. Women and girls are not required to eat any Jewish festival meals except the Passover seder meal (but they are not allowed to fast on those days).

There are two main types of bowing during the prayer services: 

• Bowing just from the waist (with and without taking steps), and
• Bowing with the knees, plus two variations on Rosh Hashana and Yom Kippur (hands and knees on floor).

I. Waist-Bowing (Two Forms)

• Modim;
• Modim in reader's repetition of amida;
• Bar'chu;
• Lecha Dodi; and
• Alenu.

          To bow this way, keep your legs straight and bend forward from your waist.
    B.  Waist-Bowing/Take Steps, for:

• Amida, and
• Kaddish.

• Bow down from waist with your legs straight.
• Take three steps backward (left foot, right foot, left foot),
• Then:
  • Bow from your waist to the left and say, oseh shalom bi'mromav,
  • Bow from your waist to the right and say, hu ya'aseh shalom alenu, and
  • Bow from your waist to the front and say, ve'al kol yisrael v'imru amen.

II.    Knee-Bowing (Three Times during Amida)

• Beginning of amida's first blessing,
• End of amida's first blessing, and
• Next-to-last amida blessing: ha'tov shimcha.

• Bend knees (at baruch),
• Bow forward (at ata), and
• Straighten up (before God's name).

III.  Knee-Bowing to Floor (Two Forms)
       A.  Knee-Bowing to Floor--Hands and Knees Only

• Kneel (with your back straight up) (at “hayu kor'im”), and
• Bow down with hands and knees on floor (at “u'mishtachavim u'modim”), but
• You are not required to touch your forehead to ground.
  Note You should still bow from your waist (but not to the floor) on Rosh Hashana--even if you are praying alone and even if there is no Torah present.

• Kneel (with your back straight up) (at “hayu kor'im”),
• Bow down with hands and knees on floor (at “u'mishtachavim u'modim”),
• Touch forehead to floor (at v'noflim al pneihem).

You must be able to recognize, from at least one piece, that an ingredient is from the ground or from a tree in order to say borei pri ha'adama or borei pri ha'eitz. If not, say she'hakol.
So say she'hakol on:

• All foods that did not grow in the ground or on a tree, but also
• Foods that you cannot personally identify as having grown in the ground or on a tree—either because it has been finely ground or processed or because you personally do not know what it is.