How is " The Poison Tree" a parable ?

A Poison Tree is not a biblical
story, although a tree is often mentioned in Genesis as the harborer of knowledge and
the place in which sin lurks. This premise colors the poem but the it is not found
literarily in the Bible. However, "The Poison Tree" can definitely be classified as
a parable.

A parable is a story told with the purpose of
teaching a moral, or a lesson. In this case, the Poison Tree is allegorical to growing
hatred within our hearts, and letting its roots anchor within our souls hence producing
nothing but poisonous feelings, and turning us into offensive
beings.

In this parable, a man is harboring a resentment
that he feels against an antagonist. He does not allow himself to analyze the feelings,
nor does confront them. He simply allows them to fester within, and grow bigger and
bigger. As they grow, the main character becomes more and more miserable, until he
finally sees his enemy dead, poisoned by his own
anger.

Therefore, the purpose of this parable is to show
that harboring anger, rancor, and holding grudges leads us nowhere. In fact, cutting the
bad emotions from their root (as if a tree) will prevent us from harvesting the products
of such negativity.