סימן צג סעיף ג
כָּל שְׁלשָׁה יָמִים הָרִאשׁוֹנִים, אֲפִלּוּ אוֹמֶרֶת שֶׁאֵינָהּ צְרִיכָה, מְחַלְּלִין עָלֶיהָ אֶת הַשַׁבָּת. וְאַחַר כָּךְ אִם אֵין בָּהּ חֳלִי אַחֵר, רַק צַעַר הַלֵּידָה, עַד שִׁבְעָה יָמִים, אִם אוֹמֶרֶת צְרִיכָה אָנִי, מְחַלְּלִין עָלֶיהָ. וְאִם אוֹמֶרֶת שֶׁאֵינָהּ צְרִיכָה, אֵין מְחַלְּלִין. מוֹנִין יָמִים אֵלּוּ מִיּוֹם הַלֵּדָה וְלֹא מֵעֵת לְעֵת, כְּגוֹן אִם יָלְדָה בְּיוֹם רְבִיעִי לְעֵת עֶרֶב, הֲרֵי הִיא בְּיוֹם שַׁבָּת לְאַחַר שְׁלֹשָׁה. וְאִם יָלְדָה בַּשַׁבָּת לְעֵת עֶרֶב, הֲרֵי הִיא בַּשַׁבָּת הַבָּאָה לְאַחַר שִׁבְעָה. וְאִם יֵשׁ קְצָת חֲֹשַֹש סַכָּנָה, שֶׁהָאִשָּׁה חֲלוּשָׁה בְּטִבְעָהּ, הַמֵּקֵל לִמְנוֹת יָמִים אֵלּוּ מֵעֵת לְעֵת לֹא הִפְסִיד.
During the entire first three days,6After giving birth. even if she says that it is unnecessary, Shabbos may be violated for her.7In order to attend her needs. [Mishnah Berurah] Afterwards, if she has no other illness, but only the [usual] pain that follows childbirth, the rule is as follows: then, up to seven days, if she says: "I require it," [Shabbos] may be violated for her sake,8Regardless whether the doctors agree or disagree. [Mishnah Berurah] and if she says it is unnecessary then it is not violated.9Unless the doctors say that she requires something. [Mishnah Berurah 330: 14] The days referred to are counted from the day of the birth and [they do] not [have to be three] twenty-four-hour periods. For example: if she gave birth Wednesday in the late afternoon, then on Shabbos it is considered more than three days [since the birth],10I.e. from the end of the birth. Notwithstanding that less than seventy-two hours have passed. The author bases this ruling on the opinion of the Magein Avraham. See Mishnah Berurah (330: 10). and if she gave birth Shabbos in the late afternoon then, the following Shabbos, it is considered more than seven days. If there is the slightest possibility of danger, because the woman is weak by nature, [then] one who is lenient, and counts full 24-hour days, is not considered wrong.11I.e. is not considered to have transgressed in any manner.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)