This is another poem unpublished during the lifetime of Clark Ashton Smith (CAS), nor was it collected in his lifetime. The text is not to be found at The Eldritch Dark, so let's start with that:
Handmaid of Beauty, yet a queen
In thine own sacred right,
Thou playest subtler chords unseen
The strains of an elusive quick delight
That Music's touch may not command
Albeit she possess
Eyes that behold the lightless land
Of ages yet unsped, and lend our sense
And magic of her vision's permanence.
Lo! in thy speech
The power and majesty that swing the sun
E'en as the worlds, and each
Dim atom of the system manifest,
Become articulate, although unguessed
The fulness of thy meaning, and unwon
The door of those dimensions enterless
That yet thou holdest, e'en as hues
That light hath wrapped in folds of clarity.
O star we may not lose
Though others pale and flee,
Thou art a Key unto the gate of Awe;
A herald of the runes I saw
In their unworded utterness;
A peak whose summit is invisible,
A plummet in the Abrupt red heart of Hell.
The ode as a poetic form has a long history, and has gone in-and-out of fashion over the centuries. Modern readers might encounter the form in something like John Keats' "Ode on a Grecian Urn", which has acquired some cultural staying power despite being over two hundred years old.
Odes often focus on praise and glorification, and have become associated with exalted emotions and a grand manner removed from common speech. So for CAS to write an ode to poetry seems a worthwhile goal, and yet for me the results fall flat. While the ideas expressed are fine, lines like "Thou art a Key unto the gate of Awe" just seem uninspired. The very dramatic last line "A plummet in the Abrupt red heart of Hell" almost seems like it was pinched from another poem, since it has a tone out-of-character with the preceding lines.