Isa is the third rune of the second aett. It is associated with the element of Ice. Ice being frozen water is solid and non-moving. It represents a resistance to change. And metaphorically it is the "Ring Pass Knot," that is spoken of in all spiritual quests. That being an obstacle or obstacles that has to be surmounted before one can go forward on their journey to higher consciousness and the God-force.
Isa corresponds to the letter "I" in the alphabet. It is connected with Verdandi, the Norn who rules the present. Since it is the present that keeps things as they are, preserves and conserves. Isa is crystallized Spirit into Matter. It is a period of absolute stillness and the solidifying factor in all things.
The rune Isa represents "intense focus" on a particular matter. It can cause one to become imbalanced, becoming obsessed by one particular subject. Materialism or pursuit of wealth could be considered such a focus.
Isa enforces the idea of unity or focus on a single point in life. This may be detrimental or lead to egomania or dull stupidity.
But there is a positive side to Isa. It is a great rune to use for protection; as it can stop or "freeze" negative forces from coming at you in their tracks. Magical warfare is rare, but if one is subject to psychic attack "this" is one of the runes to use in your arsenal.
Isa is a powerful force for concentrating the "Will" when one feels that they have become too scattered or that life has become chaotic.
"Ice," or Isa is also a way for you to constrain or constrict those elements that you wish to "freeze" or bring to a standstill.
Brightest of Blessings,