When Utnapishtim offered a sacrifice on emerging from the boat, the text says the starving gods, deprived of the offerings mortal worshippers usually provided, crowded like flies around it. Enlil, who had ordered the flood in the first place, arrived furious that any human had survived at all, but Ea rebuked him publicly for punishing the innocent along with the guilty through indiscriminate destruction, arguing that a plague or a famine would have thinned an overcrowded, noisy humanity without erasing it entirely. Persuaded, Enlil instead blessed Utnapishtim and his wife with immortality, but explicitly as a unique, unrepeatable exception rather than a status available to any other human being.
This is the detail that closes the frame story: Gilgamesh, who has sought Utnapishtim precisely to learn the secret of eternal life, is told plainly that no such secret exists for him, since Utnapishtim's case can never be repeated. The episode draws directly on older Sumerian and Akkadian flood traditions, most closely the Atrahasis epic, and stands as the nearest Mesopotamian parallel to the biblical flood story, sharing the ark, the sealing with pitch, the sequence of released birds, and the sacrifice on landing.