from the David Godman website:
Being the perfect spiritual Master that he was, Sri Bhagavan knew
well how important and necessary is the form of God for the human
mind, which is ever attached to forms. And from his own personal
experience he knew the unique power of the form of Arunachala, a
power that cannot be found in such abundance in any other form of
God, namely the power to turn the mind towards Self and thereby to
root out the ego.
In verse eleven of Sri Arunachala Patikam Sri Bhagavan exclaims
with joy and wonder, 'Lo! How many are there like me who have been
destroyed by thinking this hill to be the Supreme� ,' thereby
assuring us that if we regard this hill as God, our egos will surely
be destroyed. Though Arunachala appears outwardly as a hill of mere
insentient rock, the true devotee understands it to be the all-
knowing, all-loving and all-powerful Supreme Lord, who is guiding him
both from within and without at every step and turn of life, leading
him steadily and surely towards the goal of egolessness. 'What a
wonder! It stands as if an insentient hill [yet] its action is
mysterious - impossible for anyone to understand,' sings Sri Bhagavan
in the first line of Sri Arunachala Ashtakam.