but you must not eat: This rule is given in the same way as Israel’s Ten Commandments (see Exodus 20:1–17; Deuteronomy 5:6–21). The Lord included law and obedience in his covenant with humanity.
the knowledge of good and evil: See study note on 2:9.
you will surely die: Disobedience would bring immediate spiritual death (loss of relationship with God) and eventual physical death (see 3:22–23; Ecclesiastes 12:6–7).