Where does poetry come from? The North had an uncannily beautiful answer to this: from the blood of a wise being, brewed into mead. The story of Kvasir and the mead of poetry is murder, cunning and poetry in one – and it explains why a good verse was regarded as a divine gift.
At the beginning stands the peace between the two families of gods. As a sign of reconciliation after the war of the Æsir and Vanir, the Æsir and Vanir spat together into a cauldron. From this saliva the gods formed a being: Kvasir, the wisest that ever lived. No question could be put to him that he did not answer. He travelled through the world and taught humankind.
Two dwarves, Fjalar and Galar, invited Kvasir to their home and slew him. They caught his blood in three vessels – the cauldron Óðrœrir and the two jars Són and Boðn – and mixed it with honey. So arose the mead of poetry: whoever drinks of it becomes a poet or a scholar. To the gods the dwarves lied that Kvasir had choked on his own wisdom.
The dwarves did not keep the mead for long. After further misdeeds (they drowned the giant Gilling and slew his wife) the giant Suttung demanded the precious mead as recompense. He hid it deep within the mountain Hnitbjörg and set his daughter Gunnlöd as its guardian.
Now Odin steps onto the scene, the god of poetry and cunning. Under the assumed name Bölverk („evil-doer“) he hires himself out to Suttung’s brother, bores through the mountain in the shape of a serpent and wins Gunnlöd’s trust. Three nights he stays with her – and for this is allowed three draughts. In three mighty gulps Odin empties all three vessels, turns himself into an eagle and flies to Asgard. There he spews the mead into vessels held ready. A few drops, however, he loses on the way – this is the „share of the bad poets“, which falls free to anyone.
„Óðrœrir now has been brought up
to the holy dwelling of men.“
— Hávamál, st. 107 (after Karl Simrock, 1851, public domain)

Odin – god of poetry · The war of the Æsir and Vanir & the pantheon · The Treasures of the Gods · Ægir – ale-brewer of the gods.
Poetic Edda: Hávamál (sts. 104–110). Snorri Sturluson, Prose Edda (Skáldskaparmál: Kvasir, Fjalar & Galar, Suttung, Gunnlöd, Odin’s theft), c. 1220. English public domain: Henry Adams Bellows (1923). Research: Rudolf Simek, Dictionary of Northern Mythology; John Lindow, Norse Mythology (2001).