In the Epic of Gilgamesh, Gilgamesh fails to stay awake during Utnapishtim’s test.
Utnapishtim challenges Gilgamesh to remain awake for six days and seven nights, implying that someone unable to defeat sleep cannot expect to defeat death. Gilgamesh quickly falls asleep. Utnapishtim’s wife asks him to provide evidence of the passing days, so loaves of bread are baked and left beside the sleeping hero.
When Gilgamesh wakes, the increasingly old bread proves how long he has slept. The episode shows that his quest cannot overcome ordinary human limitations. Utnapishtim later tells him about the Plant of Life, giving Gilgamesh one final opportunity that also ends in failure when a serpent steals the plant.
Some translations vary in the details of the bread’s condition, but they consistently preserve the central test: Gilgamesh cannot remain awake.