Sumerian riddles and proverbs were copied by students studying in the eduba to become scribes. This riddle was found at Ur on a school tablet written circa 1750 B.C.E.

(What is) a house with a foundation like heaven,
A house which like a . . . vessel has been covered with linen,
A house which like a goose stands on a (firm) base,
One with eyes not opened has entered it,
One with open eyes has come out of it?
Its solution: the school.

Source: A. W. Sjoberg, "The Old Babylonian Eduba," in Sumeralogual Studies in Honor of Thorkild Jacobsen on his Seventieth Birthday June 7, 1974, edited by Stephen J. Lieberman, Assyriological Studies, no. 20 (Chicago & London: University of Chicago Press, 1976), pp. 159-179.