“There will not be a woman who loses her young or who is barren in your land. I shall fill the number of your days.”1"לֹא תִהְיֶה מְשַׁכֵּלָה וַעֲקָרָה בְּאַרְצֶךָ אֶת מִסְפַּר יָמֶיךָ אֲמַלֵּא".
This verse comes in continuation of the preceding verse. After the Torah promises:2 “And you shall serve G‑d your L-rd, and He shall bless your bread and your water, and I shall remove sickness from your midst,”הִנֵּה מִקְרָא זֶה הוּא בְּהֶמְשֵׁךְ לְמַה שֶּׁנֶאֱמַר לִפְנֵי זֶה "וַעֲבַדְתֶּם אֵת הֲוָיָ׳ אֱלֹקֵיכֶם וּבֵרַךְ אֶת לַחְמְךָ וְאֶת מֵימֶיךָ וַהֲסִרֹתִי מַחֲלָה מִקִּרְבֶּךָ",
it continues, promising: “There will not be a woman who loses her young….”וּמַמְשִׁיךְ שֶׁעַל יְדֵי זֶה לֹא תִהְיֶה גַּם כֵּן מְשַׁכֵּלָה וְגוֹ'.
These verses convey promises of blessings for the Jewish people in the three fundamental areas of concern: children, life and health, and sustenance and wealth,וְהִזְכִּיר כָּאן הַבְטָחָה עַל ג' הָעִנְיָנִים דְּבָנֵי חַיֵּי וּמְזוֹנֵי,
promising that G‑d’s blessing will be manifest amply and prodigiously.שֶׁתִּהְיֶה בָּהֶם הַבְּרָכָה בְּרִבּוּי וּבְהַפְלָגָה בְּיוֹתֵר.
“He shall bless your bread and your water” is a promise for ample sustenance."וּבֵרַךְ אֶת לַחְמְךָ וְאֶת מֵימֶיךָ" הוּא עִנְיַן מְזוֹנֵי,
The preface “He shall bless” emphasizesוּמַדְגִּישׁ בַּכָּתוּב "וּבֵרַךְ" גוֹ',
that not only will there be enough sustenance to meet one’s needs,הַיְינוּ, שֶׁלֹּא זוֹ בִּלְבַד שֶׁיִּהְיֶה הַמְּזוֹנֵי כְּפִי הַמִּצְטָרֵךְ,
but there will be increased blessing, truly abundant sustenance.אֶלָּא עוֹד זֹאת שֶׁתִּהְיֶה בָּזֶה תּוֹסֶפֶת בְּרָכָה, מְזוֹנָא רְוִיחָא.
With regard to life and health, the verse continues: “I shall remove sickness from your midst.”וּמַמְשִׁיךְ בְּנוֹגֵעַ לְחַיֵּי: "וַהֲסִרֹתִי מַחֲלָה מִקִּרְבֶּךָ",
Moreover, it promises: “I shall fill the number of your days,”וִיתֵרָה מִזֶּה, "אֶת מִסְפַּר יָמֶיךָ אֲמַלֵּא",
which is a promise of long life.שֶׁהוּא עִנְיַן אֲרִיכוּת יָמִים.
Similarly, with regard to children, it promises: “There will not be a woman who loses her young or who is barren in your land.”וְכֵן בְּנוֹגֵעַ לְבָנֵי אוֹמֵר: "לֹא תִהְיֶה מְשַׁכֵּלָה וַעֲקָרָה",
Implied is a blessing for giving birth to children, promising that no woman will be barrenשֶׁזּוֹהִי הַבְּרָכָה דְּלֵידַת בָּנִים (הַשְּׁלִילָה דַּעֲקָרָה)
and the assurance that the children will continue to thrive afterwards as well, as implied by the phrase “There will not be a woman who loses her young.”וְהַקִּיּוּם שֶׁלָּהֶם (הַשְּׁלִילָה דִּמְשַׁכֵּלָה),
Indeed, that phrase implies that the children will continue living until the parents reach old age,וּבְאֹפֶן שֶׁיִּתְקַיְּמוּ לְאֹרֶךְ יָמִים גַּם לְעֵת זִקְנָתוֹ
[as apparent from the narrative concerning Yaakov our Patriarch, when even during his old age, thinking that he had lost one of his sons, he used the expression shocholti,[כְּפִי שֶׁמָּצִינוּ בְּיַעֲקֹב אָבִינוּ, שֶׁגַּם לְעֵת זִקְנָתוֹ כַּאֲשֶׁר חָשַׁב שֶׁנֶּחְסַר לוֹ א' מִבָּנָיו,
saying:3 “As I have been bereaved of my son, I am bereaved.”]אָמַר "וַאֲנִי כַּאֲשֶׁר שָׁכֹלְתִּי שָׁכָלְתִּי"].
The root of the term שכלתי, translated as “bereaved,” is the same as that of משכלה, “one who loses her young.”
The blessing is introduced by the phrase “There will not be a woman who loses her young.”וּבָזֶה אוֹמֵר "לֹא תִהְיֶה" גוֹ',
Such a Biblical construction enables a verse to be interpreted in two ways:שֶׁיֵּשׁ לְפָרְשׁוֹ בְּב' אוֹפַנִּים,
a) as a command; and b) as a promiseבִּלְשׁוֹן צִוּוּי וּבִלְשׁוֹן הַבְטָחָה
(as we find in several other instances).4(כְּפִי שֶׁמָּצִינוּ דֻּגְמָתוֹ בְּכַמָּה מְקוֹמוֹת),
Thus the verse, “There will not be a who loses her young or who is barren” can be interpreted in two ways: a command to the Jewish peopleהַיְינוּ, צִוּוּי שֶׁלֹּא תִהְיֶה מְשַׁכֵּלָה וַעֲקָרָה
(that there not be a woman who loses her young or who is barren) – As will be explained, the command refers to the Jews’ efforts in their Divine service so that they do not reach a spiritual state that parallels “one who is barren” and “one who loses her young.”(עֶס טָאר נִיט זַיְין קֵיין מְשַׁכֵּלָה וַעֲקָרָה)
and a promise that such a situation will not come about. (There will not be a woman who loses her young or is barren.)וְהַבְטָחָה שֶׁלֹּא תִהְיֶה מְשַׁכֵּלָה וַעֲקָרָה (עֶס ווֶעט נִיט זַיְין קֵיין מְשַׁכֵּלָה וַעֲקָרָה),
Implied is that when a person does what is dependent on him so that there will not be a woman who loses her young or who is barren,הַיְינוּ, שֶׁכַּאֲשֶׁר הָאָדָם עוֹשֶׂה הַתָּלוּי בּוֹ שֶׁלֹּא תִהְיֶה מְשַׁכֵּלָה וַעֲקָרָה,
then G‑d also promises that such undesirable circumstances will not, in fact, occur.אֲזַי גַּם מַבְטִיחוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא שֶׁלֹּא תִהְיֶה מְשַׁכֵּלָה וַעֲקָרָה.

Summary

The Torah promises: “And you shall serve G‑d your L-rd, and He shall bless your bread and your water, and I shall remove sickness from your midst. There will not be a woman who loses her young….” These verses convey blessings to the Jewish people in the three fundamental areas of concern: children, life (health), and sustenance, promising that G‑d’s blessings will be manifest amply and prodigiously.
The clause “There will not be a woman who loses her young…” can be interpreted in two ways: a) as a command to the Jewish people in their Divine service; and b) as a promise: When the Jews carry out the spiritual service implied by that phrase, G‑d will fulfill the promise and bring about that blessing.