What is Shabbat?
(טז) וְשָׁמְר֥וּ בְנֵֽי־יִשְׂרָאֵ֖ל אֶת־הַשַּׁבָּ֑ת לַעֲשׂ֧וֹת אֶת־הַשַּׁבָּ֛ת לְדֹרֹתָ֖ם בְּרִ֥ית עוֹלָֽם׃ (יז) בֵּינִ֗י וּבֵין֙ בְּנֵ֣י יִשְׂרָאֵ֔ל א֥וֹת הִ֖וא לְעֹלָ֑ם כִּי־שֵׁ֣שֶׁת יָמִ֗ים עָשָׂ֤ה יְהוָה֙ אֶת־הַשָּׁמַ֣יִם וְאֶת־הָאָ֔רֶץ וּבַיּוֹם֙ הַשְּׁבִיעִ֔י שָׁבַ֖ת וַיִּנָּפַֽשׁ׃ (ס)
(16) The Israelite people shall keep the sabbath, observing the sabbath throughout the ages as a covenant for all time: (17) it shall be a sign for all time between Me and the people of Israel. For in six days the LORD made heaven and earth, and on the seventh day He ceased from work and was refreshed.
(ג) אִ֣ישׁ אִמּ֤וֹ וְאָבִיו֙ תִּירָ֔אוּ וְאֶת־שַׁבְּתֹתַ֖י תִּשְׁמֹ֑רוּ אֲנִ֖י יְהוָ֥ה אֱלֹהֵיכֶֽם׃
(3) You shall each revere his mother and his father, and keep My sabbaths: I the LORD am your God.

If God calls the Sabbath "as sign between me and the children of Israel forever," then to partake of it is to see oneself not only as an individual but as one of a people, an eternal people called at Sinai to witness to the Divine Presence in the human community. ...Each Sabbath is a link in an endless chain binding us to all the generations which have gone before and will come after "for as long as the heavens remain over the earth." Michael S. Kogon philosopher of religion

"Now I don't for a moment believe that God said at Sinai, "Do not carry money in your pockets on Shabbat," or, "Do not mow your front lawn," or even, "God to synagogue to pray" but the cumulative experience of Revelation, plus the way that experience was defined and redefined in history for a hundred generation of my ancestors, carries great weight with me." -Jewish feminist writer and activist Blu Greenberg

Talmud, Ketubot 62b

"How often are scholars to perform their marital duties? — Rav Judah in the name of Samuel replied: Every Friday night.

Talmud Brachot 57b

"Five things are a sixtieth part of something else: namely, fire, honey, Shabbat, sleep and a dream. Fire is one-sixtieth part of Gehinnom. Honey is one-sixtieth part of manna. Shabbat is one-sixtieth part of the world to come. Sleep is one-sixtieth part of death. A dream is one-sixtieth part of prophecy."

“I did not say your soul needs you to keep the Sabbath, I said your soul needs you to live in the Sabbath. If the Sabbath is a glimpse of heaven then it is more than just a time, it’s also a place we can go to receive what our souls are thirsting. The Sabbath arrives and we are invited to enter its atmosphere." -Rabbi Naomi Levy

“Meditation, music, food, prayer, learning, nature, rest. Find the paths that your soul likes best and practice them regularly until you begin to see how things are shifting within you and all around you. Take your time, let a path lead you to a deeper experience of calm, a sense of wonder, and a knowing. Soon you may begin seeing wider expanses with great perspective and less fear blocking your way. This is your soul’s vision. Welcome it.” - Rabbi Naomi Levy

Abraham Joshua Heschel, The Sabbath, pg. 28

To set apart one day a week for freedom, a day on which we would not use the instruments which have been so easily turned into weapons of destruction, a day for being with ourselves, a day of detachment from the vulgar, of independence of external obligations, a day on which we stop worshipping the idols of technical civilization, a day on which we use no money, a day of armistice in the economic struggle with our fellow men and the forces of nature—is there any institution that holds out a greater hope for man’s progress than the Sabbath?

Achad Ha'am, Shabbat and Zionism, 1898

"There is no need to be overly concerned with mitzvot in order to know the value of Shabbat. Whoever feels in their heart a true connection with the life of the [Jewish] Nation in all generations, cannot in any way imagine a reality for the people of Israel without Shabbat. One could say, without any exaggeration, that more than Israel has kept Shabbat, Shabbat has kept Israel, and if it hadn't returned to them their souls and renewed the lives of their spirit each week, all the sufferings of the "days of creation" would drag us farther and farther downward, until they would eventually descend to the bottom floor of materialism, and ethical and intellectual baseness."