Isa (ᛁ) — Ice, Stillness, Stasis

Isa (ᛁ), eleventh rune and third of Heimdall's ætt, is the rune of íss — ice, the primordial element from Niflheimr that met Múspellsheimr's fire across Ginnungagap to create the first matter. The Old Norwegian Rune Poem says: 'Íss er árbörkr' — ice is a broad river-crust, and the blind man's peril. As the simplest stave — a single vertical stroke — Isa represents absolute stasis, the frozen state where nothing can move, grow, or transform. In the cosmology of the Eddas, ice is not mere absence of heat but a fundamental cosmic substance, the necessary counterpart to fire in the act of creation.