I have a friend who, when I'm all alone,
Sits with me -- and how intimate we've grown!
He talks, but what he says he never hears,
He is unfeeling, but he dries my tears.
He has one back, he has a hundred faces
As lovely as the spring in desert places
(Sometimes I thump him on the back -- I must,
He gets half-smothered in thick, cloking dust).
He talks, but soundlessly, he has to find
A clever man before he'll speak his mind.
Whenever I encounter him, his eyes
Recall the precepts of the good and wise,
And yet he's quiet til I look his way,
Unlike some fools who blather on all day.
In darkness he falls silent -- which is right,
He is a Prince who glories in the Light.
[The answer is 'a book']