YHWH gives us His commandments as recorded by Moses written in the Torah. He doesn't give us the reason why. He just says, do this.. You must first understand He created us for his pleasure, and his pleasure is also our pleasure. Since he alone created the universe, and has our best interests at heart, who better to listen to and take every opportunity to obey? You should crave and love his commandments, like you crave and love life itself.
But we in our prideful rebellion always want to know why. It is good to question everything, but know YHWH is the one not to be questioned or opposed. Why would you of a sound mind oppose the giver of life? Nothing could be more foolish!
I believe the primary reason for the Sabbath rest, after the honoring of the creator, is for mental rest for the purpose of mental health, in the form of stress relief. Small wonder there is so much madness in the world today, as we do not observe this commandment. And any ol day is not acceptable, firstly because he commanded us to observe it on the seventh day, but also because when we all do it any ol day, we un harmoniously conflict with each other, taking away peace, causing stress. The idea is stress-free. So now ever since scripture has been written, the enemy of life has been destroying the word of Yah in the hearts and minds of people. Questioning the word of Yah: did he really mean that? Will that fruit really kill you? Is the old testament for you today? First of all, representing it as the "old testament" is a lie. Why did Yahshua die, if not so we can throw out the commandments and live however we feel like in our own minds?