The inscription is a poem which alludes to this wine cup. It mentions wine and sacrificial vessels of the Ming court. Its translation is open to interpretation, but can be read as follows:
Khotan
Why buy a toilet case or jade ring As a shabby tribute to repay generosity When it will be kept and unexpectedly
Sent far away to be carved and polished, then sent again as
tribute to another mountain
An auspicious omen in the blue sky the stars display
The happiness of the Ming court between the wine
goblet and sacrificial vessel is prolonged
The snow seeps and incense drifts, at just the right time
Thought is deferred, thirst is allayed, the whole kingdom is
blessed

Beginning in 1756, after the Qing court had suppressed the Dzungar and Moslem rebellions in Xinjiang, numerous tributes of Hindustan jade were sent to the Qianlong emperor via Xinjiang province. The jade came from the Kunlun mountains in the Khotan area of Xinjiang. The Qianlong emperor was attracted to these exotic objects and often wrote poems praising them, and some of these poems were also carved onto the bodies of the vessels themselves. A discussion of these Hindustan jades can be found in the Catalogue for the exhibition, Hindustan Jade in the National Palace Museum, Taiwan, 1983, where the above poem is listed as one of the seventy-four poems included in Qing Gaozong Yuzhi Siwen Quanji (Collected Poetry and Prose of the Qing Qianlong Emperor). It is the third poem listed on page 32 and is entitled, 'Yong Yu Chawan' (Ode to a Jade Teabowl)

Compare the very similar inscribed cup from the collection of M.H.T. Hodgson included in the O.C.S. exhibition, Chinese Jade throughout the ages, Victoria and Albert Museum, 1975, Catalogue no. 431