Both man and woman are obliged to fulfill G-d's mitzvos (precepts). The man is obligated to perform all 613 commandments. The woman, on the other hand, is excused from the performance of a few positive mitzvos which are restricted to specific time periods, in recognition of her primary obligation to family and home duties.
However, there are three precepts which are the specific prerpgative of the Jewish woman. The initial letters of these three mitzvos form the acronym HaCHayN (grace) or CHaNaH (the popular female name Channa or Hannah).
1. CHALLAH - separation of the dough being prepared for bread baking. A small portion of the dough is not kneaded into the loaf, but is put aside, a blessing is recited and the dough is later burned.
2. NIDDA - laws relating to Family Purity
3. HADLOKAS NEIROS - lighting the Shabbos and Holiday candles.
The sequence here is significant: Before there can be birth, there must be parents. The health of mother and father is dependant upon their eating: it is bread (symbolic of food in general) which holds body and soul together. But Challah must first be taken - man must dedicate a portion to G-d before satisfying his own needs. (Challah also underlines and symbolizes the woman's responsibility with regard to maintaining the Kashrus of the food).
Then follows the second mitzvah indicated by the word Nidda - Family Purity, leading to the birth of healthy children.
Finally, comes the mitzvah oflighting the Shabbos candles, which accomplishes Shalom Bayis, peace and good relations between mother and father, son and daughter.
Of these three mitzvos, two of them - separation of Challah and lighting the candles - may also be performed by the man, although they are woman's special privilege, but the one mitzvah which is entirely dependant upon her is Taharas Hamishpacha, Family Purity.
A Jewish marriage is called a Binyan Adei Ad - an "everlasting edifice". In order that the edifice of marriage should indeed be strong and lasting, everything connected with the wedding, as well as the establishment of the couple's home, should be in full compliance with the instructions of the Torah. Our Torah is called the "Torah of Life". It is the source of everlasting life in the Hereafter as well as the true guide to life on earth.
The analogy of a marriage to an "everlasting edifice" is not merely a figure of speech, but contains also an important idea and moral. In the case of any structure, the first and most important step is to ensure the quality and durability of the foundation. Without sucha foundation all the efforts put into the walls, roof, decor and so on would be of no avail.
This is even more true of the structure of marriage. If its foundation should be unstable, what tragedy would result! This is why a Jewish marriage ust, first of all,be based on the rock-solid foundation of Torah and mitzvos, then follows the blessings of joy and happiness for the rest of the beloved couple's lives.