Tirukkural 421: Fortress of Wisdom

Wisdom is a weapon to ward off destruction; it is an inner fortress which enemies cannot destroy.

Image of Satguru Sivaya Subramuniyaswami
Attachment, for instance, holds our cells together; it is also the root of much suffering, for attachment to material objects or people keeps man's awareness externalized, incapable of expressing itself in full freedom.
—Gurudeva