The Tree of Life, where there is no grasp for the Sitra Achra (the Other Side).

אילנא דחיי דלית תמן כל אחיזה לסטרא אחרא

This refers to a spiritual state or place where negative forces have no influence or hold.

Shiurim in this topic
3602. May the confirmation of your salary bring you and those who follow you more energy to do your work.
›
3772. Given the difficult situation in the Chabad Yeshivos, our contribution can only be symbolic.
›