Mitzvah of Challah: Why for Women?

The Hagahos Maimoniyos at the end of Rambam’s Sefer Zeraim collected an interesting set of sources with some of his own comments on the mitzvah of challah. He writes:

The mitzvah of challah is a great and beloved mitzvah.
The Rabbis say:
The world was created for the sake of three things: challah, tithes, and first-fruits, as it is said, IN THE BEGINNING (BE - RESHITH) GOD CREATED. Now reshith alludes to challah, for it is written, Of the first (reshith) of your dough (Num. XV, 20); again, reshith alludes to tithes, for it is written, The first- fruits (reshith) of thy corn (Deut. XVIII,4); and finally, reshith alludes to first- fruits, for it is written, The choicest (reshith) first-fruits of thy land, etc. (Ex.XXIII, 19).
--Breishis Rabbah 1:4

The Gemara says:
R. Eleazar b. R. Judah said: Because of the neglect of challah there is no blessing in what is stored, a curse is sent upon prices, and seed is sown and others consume it, for it is said, I also will do this unto you: I will visit you with terror [behalah], even consumption and fever, that shall consume the eyes, and make the soul to pine away. and ye shall sow your seed in vain, for your enemies shall eat it: read not behalah but be-challah. But if they give it, they are blessed, for it is said, ye shall also give unto the priest the first of your dough, to cause a blessing to rest on thine house.
--Shabbos 32b

The Midrash says:
R. Johanan said: Why was the passage relating to challah juxtaposed with one relating to idolatry?-To inform you that if one fulfils the precept of challah it is as if he abolished idolatry; but if one neglects the precept of challah it is as if he maintains idolatry. R. Eleazar said: It is written, For [one comes to grief] through a harlot even through a loaf of bread (Prov. VI, 26). What causes him to come to grief through a harlot?-The fact that he has eaten of her loaf which was not tithed.
--Vayikra Rabbah 15:6

This mitzvah of challah is charged to women and they are cautioned regarding it more than men. As we learn in the Talmud:

MISHNAH. FOR THREE SINS WOMEN DIE IN CHILDBIRTH: BECAUSE THEY ARE NOT OBSERVANT OF [THE LAWS OF] NIDDAH, CHALLAH, AND THE KINDLING OF THE [SABBATH] LIGHTS.
GEMARA. What is the reason of challah …? — As a certain Galilean lectured before R. Hisda: The Holy One, blessed be He, said: … I designated you the first; wherefore I commanded you concerning the first.
--Shabbos 31b

The Rambam writes regarding lighting Shabbos candles:
This duty is assigned to women rather than men, because women are usually at home doing housework. Nevertheless, the man should caution them, asking them about it and telling them and other members of his household, every Friday before it gets dark: “Light the lights!”
--Hilkhos Shabbos 5:3

Therefore, ChaNnaH, the great, righteous person, had a name that is an acronym for Ch’allah, N’idah, Hadalakas haner. She kept these three mitzvos as they were meant to be kept. That is why God gave her the desirous heart and prolific lips for prayer. And so, a woman should constantly pray when she performs these mitzvos and fulfills them punctiliously, as follows: May the Merciful One give me children who are righteous and God-fearing, and learned in the Torah [literally, Knowers of His Name, Blessed be He, as in the birkas haTorah].

The gematria of Taryag is equal to the gematria of the words: zu he mitzvas ha’challah. This is to teach you that whoever keeps the mitzvah of challah is as if they kept the whole Torah. ChaLlaH in the AB GaD method of interpretation and decoding i.e. replacing the letter in the word with the letter that precedes it in the Alfbeis, spells ZaKhU. For because of challah Bnei Yisrael merited, zakhu, to enter the Land. So also, in Parshas Shelach to teach you that they merited to enter the Land to observe the mitzvah of challah:
…When you come into the land where I bring you, Then it shall be, that, when you eat of the bread of the land, you shall offer up an offering to the Lord. You shall offer up a cake of the first of your dough for an offering; as you do the offering of the threshing floor, so shall you present it. From the first of your dough you shall give to the Lord an offering in your generations.
--Bamidbar 15: 18-21