The Jesus Prayer (
Lord Jesus Christ, Son of God, have mercy on me, a sinner. 
The prayer has been widely taught and discussed throughout the history of the
While its tradition, on historical grounds, also belongs to the
A formula similar to the standard form of the Jesus' Prayer is found in a letter attributed to
What may be the earliest explicit reference to the Jesus' Prayer in a form that is similar to that used today is in Discourse on Abba Philimon from The Philokalia. Philimon lived around AD 600.
 The version cited by Philimon is, "Lord Jesus Christ, Son of God, have mercy upon me," which is apparently the earliest source to cite this standard version.
 While the prayer itself was in use by that time,
A similar idea is recommended in the
Though the Jesus' Prayer has been practiced through the centuries as part of the Eastern tradition, in the 20th century, it also began to be used in some Western churches, including some Roman Catholic and Anglican churches.