God gave Adam and Eve the following command, followed by a cause
Genesis 2:17- 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. KJV
Even so, they ate and still lived a long life, not dying in the same day
Genesis 5:5- And all the days that Adam lived were nine hundred and thirty years: and he died. KJV
Is it as simple as "day" referring to a different period of time than it refers to today?