Lord Jesus Christ, Son of God, have mercy on me, the sinner.
It is often prayed on a knotted cord called a "komboschini" in Greek or a "chotki" in Russian as shown in the picture to the left. Komboschini come in different lengths, sometimes a bracelet-like ring of 33, sometimes in "rosaries" of 50 or 100 knots or more. While the knots are sometimes divided into groups of varying numbers, the prayer on each knot is always the same. This is different from the Roman Catholic Rosary on which we pray different prayers - Our Father, Hail Mary, Glory Be - while meditating on Mysteries.
The "Jesus Prayer" has its origins in the Desert Fathers. The Desert Fathers were a group of monks in Egypt during the early centuries of the Church. They dedicated their lives to prayer, fasting and holiness. Throughout the centuries, the "Jesus Prayer" grew in popularity among Christians of the East. I recommend The Jesus Prayer: A Gift from the Fathers, by Fr. David Hester, a priest of the Antiochian Orthodox Church for an overview of the history of this prayer.
It should be noted that there are some tensions between Catholic and Orthodox theology over certain aspects of the "object" of the Jesus Prayer, but not over the Jesus Prayer itself. If you are feeling scholarly, you might wish to pursue research on these theological tensions by reading on "hesychasm" and the theology of Gregory Palamas, whom the Orthodox consider a saint.
There are two well-known books about the "Jesus Prayer." One is a very short Russian spiritual classic called The Way of the Pilgrim by an anonymous author. The other work is a multi-volume collection on the Jesus Prayer called the Philokalia.
Pope John Paul the Great, in his Angelus Address of 11 August 1996 spoke of the Philokalia: ...Eastern spirituality has amassed a very rich experience which was vigorously presented in the famous collection of texts significantly entitled Philokalia (love of beauty") and gathered by Nicodemus the Hagiorite at the end of the 18th century. Down the centuries until our day, Eastern theological reflection has undergone interesting developments, not only in the classical areas of the Byzantine and Russian tradition, but also in the Orthodox communities scattered throughout the world. One need only recall, among the many studies worthy of mention, the Theology of Beauty elaborated by Pavel Nikolaievich Evdokimov, which is based on the Eastern art of the icon, and the study of the doctrine of "divinization" by the Orthodox scholar, Loth Borovine.
How many things we have in common! It is time for Catholics and Orthodox to make an extra effort to understand each other better and to recognize with the renewed wonder of brotherhood what the Spirit is accomplishing in their respective traditions towards a new Christian springtime.
While the Jesus Prayer is not yet as common among Western Christians as among Eastern Christians, it is growing in popularity. I encourage you to take up the practice as well and call upon the Holy Name of Jesus. Perhaps this could be your new spiritual practice for Ordinary Time when the teachings, miracles and example of Jesus is our liturgical focus.
Lord Jesus Christ, Son of God, have mercy on me, the sinner.