Why would I describe the outside of a book?

Thou shalt not judge a book by its cover.
Simply powerful words, passed directly to me
from the original source, my mother.

Books flew on and off our shelves,
they rested, waiting here and there,
hopeful, and never long forgotten.

The meat and bones, and life, between
the outer skins was understood to be
all that mattered, should you care to know.

And so, to the cover of a book, nothing
was attached. I early understood the solemn,
righteous, oath this was. And purely true.

Forever, I am grateful to my original source.