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
When we begin to meditate, we have to transmute the energies of the physical body. By sitting up straight with the spine erect, the energies of the physical body are transmuted.
—Gurudeva