Accordingly, as Buddhas enjoy objects of form, sound, and so forth, they view them without grasping, like unreal illusions. Without rejecting objects of the senses we should give up grasping them. Even if we had to abandon external objects of form, sound, etc, there would be no way to do it. It is better to give up the dualistic mental grasping within us; then the appearance of external objects can’t hurt us.
Guide to the Bodhisattva Conduct states:
Even if we tried to cover the earth
With leather, where would we get it?
With leather covering just the soles of our shoes
It is just as if we had covered the whole earth.
This is a very good example. Even if we had to cover up externally grasped objects, we could not, and it would be meaningless. Shantideva is saying that it would be better if we could take control of our own mind.
Written by Khenpo Karten Rinpoche in the book Precious Teachings, the chapter entitled “Happiness and Suffering Are Only Appearances, They Are Not Real” page 104 in the paper version and 111 of the PDF version.
