The mountain remains hidden, never fully seen.  As such, it becomes a metaphor for all the unseen realities, all the unseen mysteries of this world.

All things that move and breathe with toil and sound   our world
95  Are born and die; revolve, subside, and swell.
Power dwells apart in its tranquillity,   the world of the mountain
Remote, serene, and inaccessible
 

130  In the calm darkness of the moonless nights,
In the lone glare of day, the snows descend
Upon that Mountain; none beholds them there,   like "To M.H." by Wordsworth, the poet imagines
                                                                                a world he cannot see.

In its eternal, everlasting permanence and in its destructive power,
the mountain holds the mysteries of life and death.