Keezhmaiyai paazh sei Arunachala
Arunachala! Like the rays of the sun that illuminate all objects on earth equally, without bias, whether they are saints and criminals, temple towers and garbage dumps, ripe souls and unripe ones, you shine in the heart of every one, dispel the darkness of ignorance in us with your grace.
Even though the jiva (soul) is in reality the Self, it is deluded into identifying with the body as I, this is the lowliest (keezhmaiyanadhu*). The reason for this delusion is ignorance (avidhyai or avidya). Bhagavan is asking Arunachala to destroy this ignorance, which is responsible for all the problems a jiva is beset with. Once this is destroyed what is left is the ever-shining Self and release from all ego-identified miseries.
(*Note: TRK says keezhmayanadhu, which means the lowliest, she doesn’t qualify it as a mistake or a sin but just leaves it at that.)