The Voice of the Silence by H. P. Blavatsky
FRAGMENT III
THE SEVEN PORTALS
...Self-doomed to live through future Kalpas,* unthanked and unperceived by man; wedged as a stone with countless other stones which form the "Guardian Wall" (2

, such is thy future if the seventh gate thou passest. Built by the hands of many Masters of Compassion, raised by their tortures, by their blood cemented, it shields mankind, since man is man, protecting it from further and far greater misery and sorrow...
(2

The "Guardian Wall" or the "Wall of Protection." It is taught that the accumulated efforts of long generations of Yogis, Saints and Adepts, especially of the Nirmanakayas -- have created, so to say, a wall of protection around mankind, which wall shields mankind invisibly from still worse evils.