(Grimnismal).
Under it stands the well of wisdom for a drink from which Odin pledges his one eye.
“Gangleri said: ‘Where is the head-place or holy place of the Asar?’ Hár answered: ‘At the ash of Yggdrasil, where the gods give their judgments every day.’ Gangleri asked: ‘What can be told of that place?’ Jafnhár said: ‘The ash is the largest and best of trees; its branches spread all over the world and reach up over the heaven; three roots of the tree hold it up and spread very widely. One (of the roots) is with the Asar, another with the Hrimthursar where of yore Ginnungagap was; the third is over Niflheim, and beneath it is Hvergelmin, but Nidhög gnaws its lower part. Under the root turning towards the Hrimthursar is Mimir’s well, in which wisdom and intellect are hidden. Its owner is called Mimir; he is full of wisdom, for he drinks from the well of the horn Gjallar-horn. Odin came and asked for a drink of the well, and did not get it till he pawned his eye.”
“What more wonders,” asked Gangleri, “may be told of the ash?” Hár answered, “Many wonders. An eagle sits in the limbs of the ash and knows many things; between its eyes sits the hawk Vedrfölnir. The squirrel Ratatösk runs up and down the ash and carries words of envy between the eagle and Nidhög. Four harts run on the limbs of the ash and eat the buds; they are called Dain, Dvalin, Duneyr, and Durathror. So many serpents are in Hvergelmir with Nidhög that no tongue can number them” (Gylfaginning, c. 16).
Heid in the Voluspa tells about the holy tree, and that the horn of Heimdall is hidden under it till the last fight of the gods. Yggdrasil is watered from the water of the well.
She knows that the blast
Of Heimdal is hidden
Under the bright
Holy tree;
She sees it poured over