The World in Miniature, Container Gardens and Dwellings in Far Eastern Religious Thought, Rolf A. Stein, page 58, paragraph 2

The World, a Gourd-Shaped Vessel

The caves that make up a separate paradise are difficult to enter; entrance is by a narrow door. They are closed vessels, with a narrow throat, shaped like a gourd: "One enters by a doorway in the rock, but one cannot enter except by bending down. [Once the narrow passage is passed,] one finds a flat space of more than thirty feet. It is like a heaven [read: perfect world] within a gourd. This is why it is called gourd-heaven [hu-t'ien]" (see Fig. 27).¹⁰⁹ The entryway into the cave-heaven (tung-t'ien) of Chin-hua (or Tung-yüan) resembles that of an iron jar; through a narrow neck one enters a cave that then enlarges considerably.¹¹⁰ A separate world and a gourde shaped vessel are two inseparable ideas, even when one of the terms is not expressed (see noe 101 to this part). To the question "May one ask where you live?" one could reply "In a gourd-shaped vessel there is another world" [75].¹¹¹ These words refer to retreat (chai) in a garden (see Fig. 28). We may recall that the Ch'ang-wu-chih requires that every retreat in the mountain (shan-chai) must have a bowl garden in its courtyard (see note 94 to this part). In the miniature garden sung about by Tin Ho-nien, "sun and moon share their light in this Heaven in [the form of] a hu₁ vase.” In the same way, in a description of a bowl garden (bonseki), a Japanese author speaks thus: “If one thinks about this, one finds in it traces [of the site] of the Peach Flower Spring [t’ao-yüan; a heavenly site]….Forgetting the [ordinary] world [shih], the sun shines calmly in the gourd in the heart has this same hiding place.” ¹¹² We should note the relationship expressed between the world in the form of a gourd and the Peach Flower Spring. The heavenly nature of the other world is emphasized by alluding to the celebrated retreat site.

Stanford University Press, 1990, Stanford, 0-8047-1674-9