The lines featured are spoken as the mother who has been stung by the scorpion is presumably dying of the poison that courses through her veins. The lines are spoken by the villagers who have crowded around upon hearing of the woman being stung by the scorpion. Their words bring to light the traditional belief that the woman's soul will live on while the body dies. This faith in the universality of the soul and its immutable nature is the reason why they speak of another life, and a chance at living a life that will be different, and presumably better, than this one as the woman is dying.
May the sum of all evil
balanced in this unreal world
against the sum of good
become diminished by your pain.
The first two lines bring out the idea that what is experienced in this life in terms of evil actions done in malevolent ways is unreal, as it is not reflective of the true spirit and the vision that it brings. The idea of human consciousness is seen as a balance of evil and good done in one's lifetime is also brought out. The "unreal world" is a version of maya, or illusion. The villagers probably believe the Hindu belief that the soul must go through multiple rebirths to fully understand that the "unreal" nature of the world is this maya and that moksha, or salvation, can only be achieved through constant recognition of what is real and what is unreal. The idea that the woman's pain being endured because of the poison of the sting is something that the villagers believe will help her achieve salvation in her next birth. She experienced the worst of this "unreal world" and that this is what will allow "the sum of good" to become the mother's defining characteristic in this life, and what she takes into the next one.