The mantra Om
Mani Padme Hum (literally: "Aum, to the Jewel in the Lotus, hum)
is recited by Tibetan Buddhists to invoke Chenrezi, the Bodhisattva of Compassion.
Repeating this mantra accumulates merit and eases negative karma; meditating
upon it is believed to purify the mind and body.
Spinning prayer
wheels, physical or digital, are believed to confer the same benefit as speaking
the mantra. It is often recited with the aid of a mala
(string of prayer beads.)
You can read more
about the Om Mani Padme Hum mantra from the Dalai
Lama.