Tibetan Buddhists believe that saying the mantra (prayer), Om Mani Padme Hum, out loud or silently to oneself, invokes the powerful benevolent attention and blessings of Chenrezig, the embodiment of compassion. Viewing the written form of the mantra is said to have the same effect -- it is often carved into stones, like the one pictured above, and placed where people can see them.