What was the first law God gave Adam and Eve about the tree?
The first law God gave Adam and Eve about the tree was that in the day they ate of it, they would surely die. There was no escaping it. Ezekiel later restated the same law: the soul that sinneth shall surely die. The human race faced death because born in sin, but a loophole exists through Christ.
Les explains that the very first law, if you want to call it that, that God gave Adam and Eve concerning the tree was that the day they ate of it, they would surely die. He stresses there is no escaping it. Later, Ezekiel comes along many years later and puts the same law in different language: the soul that sinneth shall surely die. Les then applies this to the human race: we are faced with no alternative but that we have to die because we are born in sin. Yet there is a loophole. We can die in the person of Christ on the cross, by identification, by faith, by trust, that when He died, I died and you died. This connects to the larger analogy of the seed, death, burial, and resurrection, and to what Paul is stating.
But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.