What is Shabbat?
זָכוֹר אֶת יוֹם הַשַּׁבָּת לְקַדְּשׁוֹ. שֵׁשֶׁת יָמִים תַּעֲבֹד וְעָשִׂיתָ כָּל מְלַאכְתֶּךָ. וְיוֹם הַשְּׁבִיעִי שַׁבָּת לַה' אֱלֹהֶיךָ לֹא תַעֲשֶׂה כָל מְלָאכָה אַתָּה וּבִנְךָ וּבִתֶּךָ עַבְדְּךָ וַאֲמָתְךָ וּבְהֶמְתֶּךָ וְגֵרְךָ אֲשֶׁר בִּשְׁעָרֶיךָ. כִּי שֵׁשֶׁת יָמִים עָשָׂה ה' אֶת הַשָּׁמַיִם וְאֶת הָאָרֶץ אֶת הַיָּם וְאֶת כָּל אֲשֶׁר בָּם וַיָּנַח בַּיּוֹם הַשְּׁבִיעִי עַל כֵּן בֵּרַךְ ה' אֶת יוֹם הַשַּׁבָּת וַיְקַדְּשֵׁהוּ.

Remember the Sabbath day, to keep it holy. Six days you will labor, and do all your work; but the seventh day is a Sabbath to the Lord your God, in it you shall not do any manner of work, you, nor your son, nor your daughter, nor your man-servant, nor your maid-servant, nor your cattle, nor your stranger that is within your gates; for in six days the Lord made heaven and earth, the sea, and all that in them is, and rested on the seventh day; wherefore the Lord blessed the sabbath day, and made it holy.

(יב) שָׁמ֣֛וֹר אֶת־י֥וֹם֩ הַשַׁבָּ֖֨ת לְקַדְּשׁ֑֜וֹ כַּאֲשֶׁ֥ר צִוְּךָ֖֣ ׀ ה' אֱלֹהֶֽ֗יךָ (יג) שֵׁ֤֣שֶׁת יָמִ֣ים֙ תַּֽעֲבֹ֔ד֮ וְעָשִׂ֖֣יתָ כָּֿל־מְלַאכְתֶּֽךָ֒׃ (יד) וְי֙וֹם֙ הַשְּׁבִיעִ֜֔י שַׁבָּ֖֣ת ׀ לַה' אֱלֹהֶ֑֗יךָ לֹ֣א תַעֲשֶׂ֣ה כָל־מְלָאכָ֡ה אַתָּ֣ה וּבִנְךָֽ־וּבִתֶּ֣ךָ וְעַבְדְּךָֽ־וַ֠אֲמָתֶךָ וְשׁוֹרְךָ֨ וַחֲמֹֽרְךָ֜ וְכָל־בְּהֶמְתֶּ֗ךָ וְגֵֽרְךָ֙ אֲשֶׁ֣ר בִּשְׁעָרֶ֔יךָ לְמַ֗עַן יָנ֛וּחַ עַבְדְּךָ֥ וַאֲמָתְךָ֖ כָּמֽ֑וֹךָ׃ (טו) וְזָכַרְתָּ֞֗ כִּ֣י־עֶ֤֥בֶד הָיִ֣֙יתָ֙ ׀ בְּאֶ֣רֶץ מִצְרַ֔֗יִם וַיֹּצִ֨אֲךָ֜֩ ה' אֱלֹהֶ֤֙יךָ֙ מִשָּׁ֔ם֙ בְּיָ֤֥ד חֲזָקָ֖ה֙ וּבִזְרֹ֣עַ נְטוּיָ֑֔ה עַל־כֵּ֗ן צִוְּךָ֙ ה' אֱלֹהֶ֔יךָ לַעֲשׂ֖וֹת אֶת־י֥וֹם הַשַׁבָּֽת׃ (ס)

(12) Observe/Guard the sabbath day, to keep it holy, as the Lord your God commanded you. (13) Six days you will work, and do all your work/labor; (14) but the seventh day is a sabbath unto the Lord thy God, in it you shall not do any manner of work, thou, nor thy son, nor thy daughter, nor thy man-servant, nor thy maid-servant, nor thine ox, nor thine ass, nor any of thy cattle, nor thy stranger that is within thy gates; that your man-servant and thy maid-servant may rest as well as you. (15) And you shall remember that you were a servant in the land of Egypt, and the Lord your God brought you out of there by a mighty hand and by an outstretched arm; therefore the Lord thy God commanded you to keep the sabbath day.

The Sabbath, Abraham Joshua Heschel, p. xviii

The meaning of the Sabbath is to celebrate time rather than space. Six days a week we live under the tyranny of things of space; on the Sabbath we try to become attuned to holiness in time. It is a day on which we are called upon to share in what is eternal in time, to turn from the results of creation to the mystery of creation; from the world of creation to the creation of the world.