Genesis 2:9

And out of the ground made the Lord God to grow every tree that is pleasant to the sight and good for food; the tree of life also in the midst of the garden and the tree of knowledge of good and evil. This shows the manner in which the Lord prepared the garden. Jehovah God caused to sprout and grow out of the soil trees of every kind, pleasing to the eye and with fruit that was good for food, the agreeable thus being combined with that promoting health. But, above all, there was in the midst of the garden the tree of life, whose fruit would have given to man perfect health and strength always and thus prepared him for the perfection of eternal life, and the tree of the knowledge of good and evil, placed there for the purpose of testing man; for by obedience to God's command concerning it Adam would retain his concreated righteousness and holiness and progress to the perfection of heavenly bliss, while by disobedience he would become guilty of sin with all its attendant harm.