The Jesus Prayer is a contemplative and meditative prayer that we can use because while we pray it, we are also taking relaxing breathes.
The prayer is:
Jesus Christ, Son of God (Said while inhaling a breath)
Have mercy upon me for I am a sinner (Said while exhaling)
The symbolism of the prayer is one in which while praying this prayer repeatedly, we are taking in Jesus with every breath, and getting rid of sin by exhaling.