This poem ranks as something of a curiosity from the pen of Clark Ashton Smith (CAS), for while he had a lifelong interest in orientalism, the short lines and strong, punchy rhymes are not at all in line with his usual poetic practice.
The poem picks up on the sometime characterization of Sinbad the Sailor as a braggart given to great invention in recalling his legendary voyages to Sinbad the Porter. In this poem, CAS follows the device of other translators in naming the porter "Hinbad" in order to distinguish the two characters. The irony of their respective roles forms the central crux of the poem, as Sinbad "Carried upon his back the Old Man of the Sea" while:
Bemoaning his fate
Like the sad estate
Of a Baghdad porter, a Caliph's flunky—
Thus is Sinbad the Sailor portrayed as a whiner, especially in reference to his audience, the lowly Sinbad (or Hinbad) the Porter:
Sinbad, it was not well to brag
At the sunset end of your ocean-road:
For others have carried a heavier load
On aching shoulders a-sag—
A load that they could not lose.
It's certainly a minor poem from CAS, perhaps little more than a bit of fun created after a re-reading of the One Thousand and One Nights.
As an aside, it's worth noticing the unusual word "Yclept" in the final line. Even for a writer with such an extensive vocabulary as CAS, that's an uncommon, archaic word, meaning (according to the Shorter Oxford English Dictionary) called, named, or styled.