Musar zu Jeschijahu 19:5

At the end of every such seven year cycle, the earth produces ספיחים, spontaneous growth without your having either plowed or seeded. This is equivalent to the שבת שבתון concept. At the end of the chapter called מהות והנהגה, in Pardes Rimonim, the author explains that nowadays (since the expulsion from Eden) our sustenance is only the product of accretions, ספיחים, whereas when the world was perfect, i.e. when man resided in Eden, sustenance was the product of G–d's careful planning as described by the Torah in Genesis 2,10: "A river would issue from Eden to water the garden etc." This river no longer exists. This is why the Torah warned us not to harvest the grain that grows of itself, nor the grapes that grow by themselves. This type of grape alludes to the wine squeezed out by Eve out of the fruit of the tree of knowledge.