Genesis 2:17 - Joseph Benson’s Commentary on the Old and New Testaments

Of the tree of knowledge thou shalt not eat Hitherto God has been manifested as man's powerful Creator and bountiful Benefactor: now he appears as his Ruler and Lawgiver, and, as such, enters into covenant with him. He gives him but one positive precept, to try his obedience, which, as his Sovereign Lord, he had a right to do, annexing death to the breach, and, of consequence, life and immortality to the observance of it. It is evident, however, that this was not all God required of man, but that a law was written on his heart, requiring him to love God to the utmost extent of his capacity, and to imitate him in all holiness and righteousness. Thou shalt surely die The death here threatened is evidently to be considered as opposed to the life (or lives rather, Gen 2:7) which God had bestowed on him. This was not only the natural life of his body, in its union with his soul, but the spiritual life of his soul, in its union with God, and the eternal life of both. The threatening then implies: Thou shalt not only lose all the happiness thou hast, either in possession or prospect, and become liable to the death of thy body, and all the miseries which precede and accompany it; but thou shalt lose thy spiritual life, and become dead to God and things divine, and shalt even forfeit thy title to immortality, and be liable to death eternal. And all this in the day thou eatest thereof.