Good Afternoon!
When I was told my commandment I thought “what can I do with this?” Then, I looked into the commentary a little more and I saw I had a whole three pesukim! Pasuk Yud says “י֨וֹם֙ הַשְּׁבִיעִ֔֜י שַׁבָּ֖֣ת ׀ לַיהֹוָ֣ה אֱלֹהֶ֑֗יךָ לֹֽ֣א־תַעֲשֶׂ֣֨ה כׇל־מְלָאכָ֜֡ה אַתָּ֣ה ׀ וּבִנְךָ֣͏ֽ־וּ֠בִתֶּ֗ךָ עַבְדְּךָ֤֨ וַאֲמָֽתְךָ֜֙ וּבְהֶמְתֶּ֔֗ךָ וְגֵרְךָ֖֙ אֲשֶׁ֥֣ר בִּשְׁעָרֶֽ֔יךָ” in English “but the seventh day is a sabbath of your God you shall not do any work—you, your son or daughter, your male or female slave, or your cattle, or the stranger who is within your settlements.” But the seventh day. Why is Shabbat sundown Friday to sundown Saturday? For this I looked at Breishit. The pasuk I looked for was פרק ב פסוק ב: כַ֤ל אֱלֹהִים֙ בַּיּ֣וֹם הַשְּׁבִיעִ֔י מְלַאכְתּ֖וֹ אֲשֶׁ֣ר עָשָׂ֑ה וַיִּשְׁבֹּת֙ בַּיּ֣וֹם הַשְּׁבִיעִ֔י מִכׇּל־מְלַאכְתּ֖וֹ אֲשֶׁ֥ר עָשָֽׂה׃. In English this means: “On the seventh day G-d finished the work that had been undertaken: [G-d] ceased on the seventh day from doing any of the work.” The world had been busy busy busy for the past six days and now G-d is resting. Why?
Rashi says “A human being who cannot know exactly his times and moments must needs add from the week-day and observe it as the holy day (the Sabbath), but the Holy One, blessed be He, who knows His times and moments, began it (the seventh day) to a very hair’s breadth (with extreme exactness) and it therefore appeared as though He had completed His work on that very day.”
I also found another explanation from Genisis Rabbah: “What did the world lack? Rest! Sabbath came — Rest came; and the work was thus finished and completed” I like the second commentary better because it means that every day is a work day but on Shabbat the work is to rest, because that is what the world was lacking.