It is found in the Scriptures and is one of the earliest prayers in the Christian tradition. Do not think about the meaning of the word. Just give your attention to the sound of it throughout the time of your meditation, from the beginning to the end. Whenever distractions arise, simply return to your mantra. Meditate for 30 minutes each morning and each evening, every day of your life.
Meditation is a way of pure prayer marked by silence, stillness, and simplicity.