Matthew Poole and continuators on Genesis 2:9

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 .

So called either symbolically, and sacramentally because it was a sign and seal of that Life which man had received from God, and of his continual enjoyment of it upon condition of his Obedience: Or, effectively, because God had planted in it a singular vertue for the support of Nature, prolongation of Life, and the prevention of all Diseases, Infirmities and decays through age.

Or, within the Garden, as Tyrus is said to be in the midst of the Seas, Ezek. 28. 2. Though it was but just within it.

So called with respect, either, 1. To God, who thereby would prove and make known mans Good or Evil, his Obedience and Happiness, or his Rebellion and Misery. Or rather, 2. To Man, who by the use of it would know to his cost, how great and good things he did enjoy and might have kept by his Obedience, and how evil and bitter the fruits of his disobedience were to himself and all his posterity. So it seems to be an ironical denomination, you thirsted after more knowledge, which also the Devil promised you, and you have got what you desired, more Knowledge, even dear bought experience.