As stated above, the sons of Rabbi Ḥiyya say: One who did not recite havdala at the conclusion of Shabbat may recite havdala anytime over the course of the entire week. The Gemara asks: And until how many days of that week have passed may one still recite havdala? Rabbi Zeira said: Until the fourth day of the week, Wednesday, after which it is no longer considered the same week as the previous Shabbat.
This is like that ruling of halakha stated when Rabbi Zeira sat before Rav Asi, and some say it was Rav Asi who sat before Rabbi Yoḥanan. And he sat and said: With regard to the wording of bills of divorce, the first day of the week and the second and third days of the week are all called: After Shabbat. If a bill of divorce or a condition upon which the document depends includes the phrase: After Shabbat, it refers to one of the first three days of the week. However, the fourth and fifth days of the week and the eve of the day of Shabbat are called: Before Shabbat. Likewise, with regard to havdala, the first three days of the week are considered the time period after Shabbat, and therefore one may still recite havdala on these days.
Know! everything has a takhlit (a purpose/goal), and this purpose has another purpose; one more exalted than the next. For example: The purpose of building a house is so that a person has where to rest. The purpose of resting is so that with this strength, he will be able to serve God. And the takhlit of serving God….
Now, the goal of any thing is more connected to [the original] thought and intellect than the thing [itself] from which the particular goal is derived. The goal is also closer to thought than the thing is; for, “last in deed is first in thought” (Sabbath Evening Liturgy). Thus, the end and the goal is “first in thought” and close to it. And from the goal, the deed evolves.
For example: When the thought occurs to someone to build himself a house, certainly the house is not erected all at once. Rather, wood has to be prepared; each piece of lumber has to be cut and planed as is necessary. Afterwards, the house can be built and completed. Therefore, the completed house, which is the goal of the construction and its conclusion, was “first in thought.” Thus we find that the goal is closer to the thought than the beginning of the deed.
And the Jewish people themselves were created primarily for the sake of Shabbat, which is the ultimate purpose. Shabbat is the ultimate purpose for which heaven and earth were created, namely, the concept of the World of Souls (Zohar, Introduction p.1b; ibid. II, 136b), which is a world that is entirely Shabbat. There, they will perceive God properly, without any barrier and without any hindrance. For an absolute unity will manifest then, and, as our Sages, of blessed memory, taught: Each one will point with his finger [and say], “This is God, in Whom we trusted” (Taanit 31a). This is the ultimate purpose, on account of which the Blessed One created the entire creation.
2. The Six Days are the beginning, in which everything was created. Shabbat is the end and ultimate purpose…. And there certainly are distinctions between the creations, because there certainly are differences between that which was created before and that which was created on Day Six, which is closer to Shabbat. Thus it is brought in the holy books: “six days God made heaven and earth” (Exodus 31:17)—that also the Six Days themselves were created. Kabbalistically, they are [points that form] a circle around an inner point, which is Shabbat (Zohar II, 204a)...
(טו) וְזֶהוּ שֶׁאָמְרוּ רַבּוֹתֵינוּ זִכְרוֹנָם לִבְרָכָה (מכילתא ועיין ביצה טז.) בְּשַׁבָּת: זָכְרֵהוּ מֵאֶחָד בְּשַׁבָּת, הַיְנוּ שִׂמְחַת וְתַעֲנוּג עוֹלָם הַבָּא, שֶׁהוּא בְּחִינַת שַׁבָּת, יַרְגִּישׁ בְּשֵׁשֶׁת יְמֵי הַמַּעֲשֶׂה, שֶׁהֵן בְּחִינַת מַעֲשֵׂה הַמִּצְווֹת, שֶׁבָּהֶם נִבְרְאוּ עוֹלָם שָׁנָה נֶפֶשׁ.
(15) This is the meaning of what the Sages said concerning Shabbat: Remember it from the first day of the week (Mekhilta, Yitro 7; Beitza 16a). The joy and pleasure of the World to Come, which is an aspect of Shabbat, should be experienced during the six days of work. [These six weekdays] correspond to the performance of the mitzvot, because World-Year-Soul were created on them.
(ו) בְּיוֹם קָדְשִׁי – יִדְמֶה כְּאִלּוּ עַכְשָׁו יוֹם קָדְשִׁי. הַיְנוּ שֶׁתַּמְשִׁיךְ מִקְּדֻשַּׁת שַׁבָּת עַל יְמֵי הַחֹל, וְתַקְדִּישֵׁם מִשְּׁלֹשִׁים וְתֵשַׁע מְלָאכוֹת.
(6) on My holy day — it should seem as though this is “My holy day.” You should draw from Shabbat’s holiness to the days of the week and so sanctify them from the thirty-nine works.