A popular critical theory suggests that the epilogue of Qohelet, which recommends discipline and piety, is a later addition aimed at reconciling the unorthodox ideas of the book with conservative views. While this hypothesis is well-established on the basis of the text’s style and content, no external evidence to support it has ever been suggested. This paper seeks to present an empirical model for this redactional theory from a comparative point of view. It examines the development of the vanity theme in Mesopotamian literature, and shows that the subversive ideas of vanity literature gave rise, from the very beginning, to redactional activity focused on re-interpreting it in light of traditional values. Several examples of this process of conservative redaction are discussed, including Sumerian, Akkadian, and Akkadian-Biblical cases. The theory that the final verses of Qohelet are a later interpolation thus gains credibility in light of similar phenomena in Mesopotamian literature.