This doesn't seem right: Epic of Gilgamesh is the oldest known Mesopotamian work of fiction and it's a more recent ~2,100 BCE [0].
The historic person Sargon of Assad lived in the 24th/23rd century BCE [1]—are they perhaps confusing his biographical era, with the era when (surviving, extant) poetic epics were written about him? His Wikipedia entry [1] doesn't seem to mention any written works older than 8th century BCE.
edit: I've tracked down [2] what I think is the original source of the "city of saffron" quote. It's from an "autobiography" of Sargon which seems to be a much, much later (7th century BCE?) work of fiction—not a historical autobiography (see the introductory discussion starting page 16).
- "4. As has already been noted, no such city has been located, but its meaning, “a specific azupiru-like spice and medicinal plant, is well known. Note, however, the logogram U.HURSAG would mean ‘Mountain Plant’ in Sumerian, which may be related to Sargon’s supposed origins in the highlands. This herb was also used as a potion to produce abortions, which may lend a double entendre to this so-called place-name."
[0] https://en.wikipedia.org/wiki/Epic_of_Gilgamesh
[1] https://en.wikipedia.org/wiki/Sargon_of_Akkad
[2] https://archive.org/details/resgestaesargonis/page/39/mode/2... (Joan Goodnick Westenholz, "Legends of the kings of Akkade : The Texts" (1997), page 39, footnote 4)
https://oracc.museum.upenn.edu/epsd2/cbd/sux/o0024740.html (Electronic Pennsylvania Sumerian Dictionary, ePSD2: "azugna [VEGETABLE] (N)")
(footnote: I'll never not be amazed modern web browsers support 4,000-year-old writing systems. Look, it's 𒀭𒄑𒉋𒂵𒎌!)