God told Adam not to eat of the forbidden fruit. Adam and Eve did anyway. That was a sin because they broke God's command.
Where in scripture does it say God told Cain not to murder? If it does not then (back then) murder could not be a sin right?
"Sin is the transgression of the law."
"By the law is the knowledge of sin."
"Where no law is there can be no transgression."
I think I quoted those accurately enough from memory. I bet you know those verses.
Cain did no wrong killing Abel (or even giving the wrong offerings to God) unless there were explicit commands from God concerning those things. The bible records none.
Stating that the bible does not record a command to keep the sabbath day from Genesis until the Exodus is not proof THERE WAS NO SUCH COMMAND.
If there was no law before the flood then God was unjust killing off practically the entire human race. What sins did they commit? The bible does not say. It only says their imaginations were evil. How do you know good from evil without a God given directive?
Did Abraham sin when he told Pharaoh his wife was not wife but sister? Where is the command concerning adultery? Why was Pharaoh punished?
Why did Joseph reject Potiphar's wife? (Gen 39:9) It was a sin against God. Where from Adam to Joseph is that command?
Lack of evidence does not prove one way or the other whether the sabbath was binding on humanity before the Exodus or not.
"Your Honor. I walked into a dark room and smelled rotting dead meat. I think there's a body in there."
"Did you actually SEE the dead body?"
"No your Honor the room was dark..."
"In that case this court rules that there WAS IN FACT a dead body in that room that nobody ever saw."
RIIIIGHT.
You’re right that “lack of explicit command” doesn’t prove “no law at all”—but that cuts against your case, not for it.
Scripture clearly teaches pre‑Sinai moral accountability (Rom 2:14–15; 4:15):
Cain’s murder, Pharaoh’s adultery‑adjacent actions, the pre‑Flood world’s corruption—all condemned because God’s moral law is written on the heart, even before it’s codified at Sinai.
That’s exactly the point: moral law (don’t murder, don’t commit adultery, don’t lie) is universally binding and evident in Genesis; the Sabbath command is not.
Genesis never shows Adam, Cain, Noah, Abraham, or Joseph keeping a weekly seventh‑day; the first explicit giving of Sabbath as a commanded sign is to Israel in Exodus 16/31, and it is explicitly called the sign of that covenant (Ex 31:13–17), not of creation or of humanity in general.
So yes—there was real law before Sinai, but that proves the opposite of what you’re arguing: if Sabbath were part of that universal moral law, we’d expect it to appear in the same way murder, adultery, and deceit do in Genesis.
Instead, the NT treats Sabbath as a shadow (Col 2:16–17) and locates its substance in Christ’s rest (Heb 4), while continuing to condemn murder, adultery, and lying as direct violations of God’s moral will.
Your courtroom analogy fails because we do “see the body” for moral law in Genesis; we only “smell something” for Sabbath, and the text itself later identifies it as a covenant sign for Israel, not a creation ordinance for all.