For how many days did Odin hang on Yggdrasil to gain knowledge?

Odin hung on Yggdrasil for nine days—traditionally described in the source poem as nine nights—to gain knowledge of the runes. The ordeal is recounted in stanza 138 of Hávamál, part of the Poetic Edda.

Odin describes sacrificing himself to himself on a windy tree. He is wounded by a spear, deprived of food and drink, and left hanging until he perceives and grasps the runes. The runes are not merely an alphabet in this story; they represent powerful forms of knowledge connected with magic, wisdom, fate, and poetry.

Hávamál does not explicitly name the tree as Yggdrasil, calling it a windswept tree whose roots are unknown. Nevertheless, commentators commonly identify it with Yggdrasil because of the tree’s central role in Norse cosmology and the likely meaning of Yggdrasill as “Odin’s horse,” a poetic reference to a gallows.

The number nine also echoes other Norse traditions, including the Nine Worlds and Yggdrasil’s three roots. A frequent wording difference is “nine nights” rather than “nine days”; both refer to the same nine-night ordeal, with “nine days” common in modern retellings.