Isa is the vowel I (pronounced ee)
Anglo-Saxon Rune Poem (from ragweedforge.com)
Ice is very cold and immeasurably slippery;
it glistens as clear as glass and most like to gems;it is a floor wrought by the frost, fair to look upon.
Isa, the rune of Ice, is a rune of freezing, stillness, cold and silence. In the early 20th century Runic renaissance in Germany, most esotericists saw it as the main rune to use in the beginning, as a way of bringing stillness to the energies within, a kind of runic zen meditation to bring stillness and emptiness to your being. It still works well for that purpose, as the stillness that it can bring can often bring clarity and a greater sense of self to the user. In a reading it can indicate when forces become stopped or frozen. You might be stuck in a situation or a mindset, and until you can be released, you are frozen, often repeating the same behavior. It can also show an opportunity to be still, and have a moment of rest and solitude, before venturing out again to deal with the world around you again.
Isa is one of the rune of the key cosmological forces of the Northern Tradition. It’s opposite is Cweorth, the Fire-twirl, as it embodies the force of Fire. From the meeting of Fire and Ice, the void was filled, and the first beings came into being, first a cow named Audhumla, and then a massive Frost Giant, Ymir. At it’s strongest, Ice is complete stasis, o degree Kelvin as it were, where nothing moves, changes or can be altered. It is only when Fire, the force of action, change and transformation is brought in the Ice melts away, revealing what was locked inside and setting it free. But, also in reverse, Ice can bring stillness to overwhelming activity, slowing down the change, allowing it time to set in, before it changes again. Too much Fire can be as damaging or difficult as too much Ice. It is in the balance of these forces that Life and Creation is found.