Mantras are prescribed syllables to protect the mind. What we want to protect our mind from are attachment, anger, ignorance, and so on. When combined with the four opponent powers, mantra recitation is very powerful in purifying negative karmic imprints on our mindstream. While we recite mantras, we should also be thinking and visualizing in a beneficial way so that we are building up constructive habits in the mind.
In the Vajrayana practice, mantras are recited in Sanskrit, rather than being translated into other languages. The reason for this is that there is a special beneficial energy or vibration that is induced by the sound of the syllables. While doing recitation, we can concentrate on the sound of the mantra, on its meaning, or on the accompanying visualizations that the master has taught.
