Pandora opens the jar that releases troubles into the world in Hesiod’s Works and Days.
The poem presents the episode as an explanation for the suffering found in human life. Before Pandora’s arrival, evils are contained; after she opens the vessel, they escape and spread among mortals. The text’s wording concerns a large storage jar, not a small modern box.
The story belongs to Hesiod’s didactic poem about agriculture, justice, work, and human conduct. It is not narrated in Homer’s Iliad or Odyssey, even though those epics are often grouped with Hesiod’s works as major early Greek literature.
Later European translations and artistic adaptations popularized the phrase “Pandora’s box.” That phrase can make readers assume the original story appeared in a separate mythological tale or in Homer. The specific surviving literary source for the opening episode is Works and Days.