Om mani padme hum

Om mani padme hum (Devanagari ॐ मणि पद्मे हूँ, IAST ) is probably the most famous mantra in Buddhism, the six syllabled mantra of the bodhisattva of compassion, Avalokiteshvara (Tibetan Chenrezig). The mantra is particularly associated with the four-armed Shadakshari form of Avalokiteshvara. The Dalai Lama is said to be an incarnation of Chenrezig or Avalokiteshvara, so the mantra is especially revered by his devotees and it is commonly carved onto rocks and written on paper which is then inserted into prayer wheels to increase its effects.
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Om Mani Padme Hum (Sanskrit) Om! the jewel in the lotus, hum! One of the most sacred Buddhist mantras or verbal formulas; used very frequently in Tibet and in surrounding countries of the Far East. Not only is every syllable said to have a secret power of producing a definite result, but the whole invocation has a number of meanings. When properly pronounced or changed, it produces different results, differing from the others according to the intonation and will given to the formula and its syllables. This mystic sentence above all refers to the indissoluble union between man and the universe, and thus conveys "I am in thee and thou art in me." Each of us has within himself the jewel in the lotus or the divine self within. When understood in a kosmic sense, it signifies the divine kosmic self within, inspiring all beings within the range of that kosmic divinity.