A law is nothing more than something established. Like the law of gravity or entropy. We are made in God's image and likeness. That is a law, something established, that just is. With that in mind, let's take a look at the law in Deuteronomy 30:10-14. There we will find that they who would come to God, at that time Israel or the stranger within their gates are instructed to hearken unto the voice of the Lord, keeping of the commandments and statutes contained in the Book of the Law. And that this Word is in our hearts and mouths that we do it. Please note that it doesn't say put in, but that it is in. Therefore, it is something that is established, therefore a law. Which makes sense, since we were made in His image and likeness. One should also note that verse 10 does not mention the judgements. That is because there is No need for them if we are living according to how we are made. Being made in His image and likeness, with His word in our hearts and mouths. This law is also paraphrased in Romans 10:6-8 showing it's implications in and through Christ. This can also be seen in Acts 17, where Paul says to pagans, for in him we live, and move, and have our being; as certain also of your own poets have said, For we are also his offspring. His use of the word "we" includes those to whom he was speaking. Which makes sense, since we are all made in His image and likeness. And part of that since the Garden of Eden is hearkening unto His voice. For in Him we live, move and have our being.
So with that in mind, our bodies have a natural 7-day rest cycle. This natural 7-day rest cycle is bound up in all of biology. Almost, if not everything that has a body, from insects to fish to mammals, has a natural built in, 7-day cycle. It's in our genetics and is called the “Circaseptan rhythm”.
According to the field of chronobiology, almost, if not all life operates on this cycle, and the biological need for rest. Despite being exposed to different
environmental and social factors, these rhythms continue to persist, indicating that it may be inherent in origin. iIn other words We need rest every 7th day regardless of our environment.
It is interesting that almost all, if not creation that has a body has this Circaseptan rhythm and on the 7th day God rested and WAS refreshed. Couple that with the fact that He did so is the reason why he reminded us of ALL the moral instructions and included the rest on the seventh day, since we are made in His image and likeness. IT IS THE BEST TIME TO DO SO. But Not only us, but the very creatures, livestock to which we have taken under our care are to do so, that they have rest and be refreshed at the best possible time that is given in relation to the genetic rhythm in all that God gave a body. Despite being exposed to different environmental and social factors, as was said, these rhythms persist, which indicate that it is inherent in origin. And Being made in God's image likeness show us that it is inherent. And when we fell away in Eden is why God reminded us of the Sabbath and taught us to keep it, to protect us and creation from harm and live to our full potential. Incidentally, the busy Beaver and, Bee and various species of birds have been observed in this cessation from work on Saturday. Which is a powerful testimony also in respect to the 7th day being the day of rest.
If we would define moral instruction we would say that these instructions are that which keep us and society from harm.
The following is an excerpt from a study found at the National Library of Medicine. Link embedded.
What is the significance of the 7 d activity/rest cycle, i.e. week, storied in the Book of Genesis and adopted by the Hebrews and thereafter the residents of nearby Mediterranean countries and ultimately the world? Why do humans require 1 d off per 7 d span? Do 7 d rhythms bestow functional advantage to organisms? Is the magic ascribed to the number 7 of relevance? We hypothesize the 7 d time structure of human beings is endogenous in origin - a hypothesis that is affirmed by a wide array of evidence - and synchronized by sociocultural factors linked to the Saturday (Hebrews) or Sunday (Christian) holy day of rest. We also hypothesize they are representative, at least in part, of the biological requirement for rest and repair 1 d each 7 d, just as the circadian time structure is representative, in part, of the biological need for rest and repair each 24 h.
When our mind is already made up and we think we know something, what is possibility of it being changed?