Sages teach 
that 613 mitzvos were given to the Jewish people at Mount Sinai. "David... condensed them into eleven, as it is written, 
'He who walks uprightly and acts justly, and who speaks the truth in his heart....' Yeshayahu... condensed them into six, as it is written, 
'He who walks righteously... and shuts his eyes from seeing evil.' Michah... condensed them into three, as it is written, 
'To act justly, to love kindness, and to walk humbly with your G-d.' Chavakuk... condensed them into one, as it is written, 
'A righteous man lives by his faith.'"
Obviously enough, these prophets did not reduce the number of mitzvos. Rather, they highlighted the dominant thrusts which, when internalized, upgrade one's observance of all the commandments. 
A similar concept applies to the three fundamental mitzvos which our Sages  associate with Jewish women:
- challah - the separation for the Kohen of a portion of the dough being prepared for baking, and by extension,  the preparation of kosher food in its entirety;
- niddah - the observance of the Torah's guidelines for maintaining the purity of marital life; and
- hadlakas haner - the lighting of candles to usher the Shabbos and festivals into our homes.
As will soon be seen, their dominant thrusts span the entire gamut of commandments that women observe.
The name Chanah serves as an acronym for the Hebrew names of these three mitzvos, for the prophetess Chanah serves as a paradigm for Jewish women. 
The Biblical narrative as expounded in the Midrashim underscores her unique contributions as a wife and as a mother, and accentuates her activities beyond her household through which she inspired the Jewish people as a whole.
These three mitzvos lead to precisely the same goals:
They help a woman to weave the physical and spiritual fabric of her home, to forge a link to posterity, and to transform her home into a lantern that will illuminate its environment.
When rearranged, the letters of the name Chanah also form the word hachen, which means "grace", and thus points to the quality which characterizes a woman's observance of these mitzvos.
Moreover, this association also implies that the observance of these mitzvos amplifies the gentle grace which is an innate gift of women.
In particular, each of these mitzvos contributes a lesson of its own.
The observance of the commandment of challah (and, by extension, maintaining a kosher diet) shows the uniqueness of the Torah lifestyle: the fusion between the spiritual and the material realms that it encourages.
For the Torah's spiritual truth was never intended to be confined to some sphere that wafts above our physical reality; it is meant to permeate the realm of physical experience.
Even eating, drinking, and other physical activities in which Jews appear to resemble the other nations, are to be carried out in a manner which expresses the connection we share with G-d.
To see how this ideal is translated into actuality, we need only look at the mitzvah of challah.
When one's dough has been kneaded, part of it is set aside, distinguished as holy, and given to a priest.
This gift is not a sacrifice to be burnt on the altar: it is eaten. The pattern thus established, the separation and elevation of materiality, should be extended to all aspects of our interaction with our material environment.
First, we must set aside and distinguish a certain portion - indeed, the choicest portion - of our mundane endeavors.
By elevating this sample, and accentuating its spiritual dimension, we simultaneously elevate the entire remaining range of these endeavors.
This insight sheds light on a perplexing Talmudic passage. Our Sages ask,  "How does a woman help a man?" - and they answer with rhetorical questions: "If a man brings home wheat does he chew it? If [he brings home] flax does he wear it? If so, does she not bring light to his eyes and put him on his feet?"
What lies at the heart of this seemingly simplistic summary of a woman's wifely functions? Is its focus on mere materiality? These questions can be resolved by examining the ultimate source for all male-female relationships: the bond between G-d and the Jewish people which our Sages compare to a marriage link.
The home for this ultimate couple is our world, which G-d created with the intent that it serve as His dwelling.
Yet though He created the raw materials for its construction, He delegated to the Jewish people - His wife, as it were - the responsibility of processing these raw materials, and infusing them with spiritual purpose.
In microcosm, this is the task performed by every Jewish woman in her homemaking efforts.
And this affects the macrocosm, the universe - for ordinary activities, such as processing wheat and flax into useful artifacts, are the very stuff with which G -d's ultimate desire is fulfilled.
Executing this task has far-reaching benefits.
On the most obvious level, a woman is responsible for the physical health and well-being of those who depend on her judgment.
Beyond that, since the food one eats is quite literally transformed into one's own flesh and blood,  there is a responsibility for the effects of this food on the family's tendencies and character traits.
If, for example, a person eats an animal of prey, then while its flesh is being digested in his stomach, its tendency to cruelty percolates imperceptibly through to his soul. 
Finally, over and above the effects of a person's eating habits on his middos, there is a comparable effect on his mode of thinking:  coarse and gross food predisposes the mind to coarseness and grossness, whereas refined food makes its perception clearer and more refined. 
Though these concepts are also relevant to men, the responsibility in this area is primarily a woman's: the choices as to her household's diet are mainly hers.
The inextricable bond between material and spiritual is further tightened by the next of the three mitzvos - observance of the laws of niddah, and adherence to the Torah's directives concerning family life.
Here, too, a basic physical activity  draws down the highest spiritual energies: it is through conception that the Ein Sof, G-d's infinity, is revealed. 
The Torah's guidelines enhance the relationship between a woman and her husband and endow it with purity. Above all, these guidelines nurture eternity, since they prepare for the conception of children in holiness.
For a soul to function in all its pristine refinement and purity even while enclothed in a body, it needs to be summoned down to this world in conditions of refinement and purity.
In other words, the newborn body which is to host it for a lifetime needs to be conceived according to the principles that govern family purity, taharas hamishpachah.
This prior condition affects the "garments" of the soul,  i.e., the means by which the soul finds expression in the body. 
This mitzvah, too, is also relevant to men; indeed, the very name "family purity" is a reminder that this mitzvah affects the entire family.
Nevertheless, the responsibility for its observance centers on women. This primary responsibility finds explicit expression in Torah law,  which grants a woman unique authority to define the state of ritual purity that determines the periodic resumption of relations.
One of the special gifts of women is - generating light.
This is the contribution of the third mitzvah, the lighting of candles in honor of Shabbos and the festivals. 
Just as in a physical sense, a candle reveals the otherwise- unseen contents of a room, so, too, in a spiritual sense, the Shabbos candles of Jewish women and girls reveal the unseen and intangible G-dly energy which permeates our existence.
The spiritual light generated by a woman's Shabbos candles illuminates the home, not only on Shabbos, but also during the weekdays that follow.
In this vein, the Midrash  tells us that the Shabbos lamps kindled by Sarah Imeinu, our matriarch Sarah, continued to burn for an entire week.
Moreover, this miracle repeated itself whenever her daughter-in- law, Rivkah Imeinu, lit candles. And, less visibly, the same miracle occurs whenever a Jewish woman or girl lights her Shabbos candles.
It will be noted that Rivkah Imeinu lit her candles before marriage.
From her example we see what a three-year-old  Jewish girl can do: she can kindle lamps which will radiate light for an entire week.
Every little Jewish girl who is old enough to appreciate the significance of what she is doing can mirror that light - by lighting candles every Friday, and before every festival.
The more candles lit around the world, the more light. For even  "a l ittle light dispels a great deal of darkness."
And the increase in the spiritual darkness that beclouds the world today has to be met by an increase in spiritual light - by  "a mitzvah [which] is a candle and by the Torah [which] is light," and, in a most literal sense, by the mitzvah-candles lit every Friday night.
Though this commandment, too, obligates men as well as women, it has been entrusted to those in whose hands its observance is most powerful.
To refer back to the Midrash mentioned above:
Although Abraham lit Shabbos candles after Sarah's death, they did not burn throughout the week.
That enduring achievement was the prerogative of Sarah, representing all Jewish women, and of Rivkah, representing all Jewish girls.
We have G-d's longstanding promise: 
"If you cherish the lights of Shabbos, I will show you the lights of Zion."
Shabbos is a foretaste of  "the Day which is entirely Shabbos, and repose for life everlasting," i.e., the World to Come.
Kindling Shabbos candles anticipates - and precipitates - the enlightenment of that future era.
Similarly, the purifying waters of taharas hamishpachah clear a path for the Redemption.
For, as our Sages explain, the coming of the Redemption is dependent on the birth of more and more children. 
In that age, moreover, we will merit the fulfillment of the prophecies,  "I will sprinkle upon you purifying waters and you will become pure," and  "I will remove the spirit of impurity from the earth."
The mitzvah of kosher food is also connected with the era of which it is written,  "I will destroy dangerous animals within the land"; beasts of prey will cease to exist.
Moreover, G-d will prepare a feast for the righteous, and their partaking of it will depend on newly-revealed insights into the laws of kashrus. 
Ultimately, sprouting out of all the day-by-day physical/spiritual wedding preparations in the home of G-d's eager and industrious "bride", the marriage bond between G-d and the Jewish people will blossom into consummation.
In that age we will merit the fulfillment of the prophecy,  "I will greatly rejoice in G-d... for He has clothed me with the garments of salvation..., as a bridegroom garbs himself in priestlike apparel, and as a bride adorns herself with jewels."
- (Back to text) The above essay is adapted from talks of the Rebbe as published in Likkutei Sichos: Vol. XIII, pp. 256ff., 259ff., 274ff., 280ff., 295ff.; Vol. XVIII, p. 157; Vol. XX, p. 227; Vol. XXIX, p. 498ff. See also Sefer HaSichos 5751, p. 566ff.; sichos of 26 Sivan, 5729.
- (Back to text) Makkos 23b.
- (Back to text) Tehillim 15:2.
- (Back to text) Yeshayahu 33:15.
- (Back to text) Michah 6:8.
- (Back to text) Chavakuk 2:4.
- (Back to text) Cf. Likkutei Sichos, Vol. XVIII, p. 157, et al.
- (Back to text) Talmud Yerushalmi, Shabbos 2:6; Tanchuma, beg. of Parshas Noach; Bereishis Rabbah, end of sec. 17; Or HaTorah, Parshas Shlach, p. 535ff.; Toras Shmuel 5627, pp. 309ff. & 315ff.
- (Back to text) Bread, for example, as man's staple food, sometimes signifies an entire meal (as in I Melachim 5:2 and II Melachim 25:29), or, in a broader sense, all our material needs.
- (Back to text) I Shmuel, chs. 1-2. The source for the above-quoted acronym is Megaleh Amukos on the Torah, Parshas Shlach, s.v. Gimmel mitzvos, sec. 17:4, citing the author of Haggahos Maimuni.
- (Back to text) Yevamos 63a.
- (Back to text) Cf. Tanya, ch. 8.
- (Back to text) See Ramban (cited by Rabbeinu Bachaye) on Vayikra 11:13; Akeidah, Abarbanel, and others, loc. cit.; Ramban on Devarim 14:3; R. Moshe Isserles, Yoreh Deah, end of sec. 1:7; and elsewhere.
As the Rebbe observes (in Likkutei Sichos, Vol. III, p. 984ff., and footnotes there), this insight enables us to understand why a nursing mother who has eaten forbidden food, even when permitted to do so because her life was endangered, should refrain from nursing her child. (See Taz (Turei Zahav) and Shach (Sifsei Kohen) in Shulchan Aruch, Yoreh Deah, end of sec. 81.)
For although eating this food was in fact halachically permitted, the nature of the food and the spiritual blemish which it imparts to her infant remain unchanged.
(Cf. Rambam, Hilchos Shabbos, beg. of ch. 2.)
- (Back to text) Cf. Keser Shem Tov, sec. 381 (also sec. 186), citing the writings of the Rambam.
- (Back to text) See, e.g., Shelah, Shaar HaOsiyos, sec. 85b.
- (Back to text) The Rebbe notes that these three mitzvos all share a significant characteristic: they all deal with basic needs and activities that are shared by all of humanity - the provision of light, the preparation of food, and the maintenance of family life. What is required of a Jew is that he transform these human activities into Jewish activities. See Likkutei Sichos, Vol. XX, p. 227.
- (Back to text) See the maamar beginning Kol HaNeheneh 5652; see also Likkutei Torah, Shir HaShirim, p. 40a.
- (Back to text) It also affects the physical health of the body; see: Sefer HaSichos 5700, p. 19ff.; Likkutei Dibburim (in English translation: Kehot, N.Y.), Vol. III, ch. 21, sec. 25; and Vol. IV, in the first Appendix to ch. 30. See also the sources enumerated in the next footnote.
- (Back to text) Zohar II, 3b; cf. Tanchuma, beginning of Parshas Metzora; Vayikra Rabbah 15:5; Ramban on Vayikra 18:19; Tanya, end of ch. 2; and elsewhere.
- (Back to text) See Shulchan Aruch, Yoreh Deah, ch. 185:1.
- (Back to text) The farbrengen on this subject on Shabbos Parshas Chayei Sarah, 5735  (see Likkutei Sichos, Vol. XV, p. 163-173) was originally adapted and published as an essay entitled "The Shabbos Lights" by Sichos In English.
- (Back to text) Bereishis Rabbah (and Rashi) commenting on Bereishis 24:67. These sources also allude to the other two mitzvos of which we have spoken, for in the case of both Sarah and Rivkah, "there was always a blessing in the dough" (an allusion to the mitzvah of challah), and "a cloud hovered over the tent" (an allusion to taharas hamishpachah, for the cloud distinguished this dwelling's holiness).
- (Back to text) Rashi on Bereishis 25:20.
- (Back to text) Tzeidah LaDerech, sec. 12.
- (Back to text) Mishlei 6:23.
- (Back to text) Yalkut Shimoni, Parshas Behaalos'cha, sec. 719.
- (Back to text) Tamid 7:4.
- (Back to text) Yevamos 62b; see also the above essays entitled "Family Planning" and "Three Mothers."
- (Back to text) Yechezkel 36:25.
- (Back to text) Zechariah 13:2.
- (Back to text) Vayikra 26:6.
- (Back to text) Vayikra Rabbah 13:3.
- (Back to text) Yeshayahu 61:10.