“Who when he had heard, that it was Jesus of Nazareth, began to cry out, and to say: Jesus son of David, have mercy on me. And many rebuked him, that he might hold his peace; but he cried a great deal the more: Son of David, have mercy on me.”
The Jesus Prayer
From the early Church Fathers to now.
Lord Jesus Christ, Son of God, have mercy on me, a sinner.
Shorter forms are also used — "Lord Jesus Christ, have mercy on me," or simply "Lord, have mercy" (Kyrie eleison). In the hesychast tradition the words are repeated slowly and without ceasing, often in rhythm with the breath, until the invocation becomes the unceasing "prayer of the heart."
“And the publican, standing afar off, would not so much as lift up his eyes towards heaven; but struck his breast, saying: O God, be merciful to me a sinner.”
“O God, make speed to save me: O Lord, make haste to help me, for this verse has not unreasonably been picked out from the whole of Scripture for this purpose. For it embraces all the feelings which can be implanted in human nature, and can be fitly and satisfactorily adapted to every condition, and all assaults.”
In the fifth century Diadochus, Bishop of Photike, counsels the unbroken inward repetition of the name of the Lord Jesus as the way to gather the scattered mind — an early witness to the prayer of the Name in the Christian East.
In The Ladder of Divine Ascent, St. John Climacus of Sinai gives the remembrance of the name of Jesus a central place in the monk's unceasing prayer, joining it to the very rhythm of the breath — an image that becomes central to the later prayer of the heart.
The "prayer of the heart" practised by the monks of Mount Athos is challenged, and then defended, by St. Gregory Palamas; the councils of Constantinople of 1341, 1347 and 1351 vindicate the hesychasts and their prayer.
St. Nicodemus of the Holy Mountain and St. Macarius of Corinth gather the great hesychast texts on the prayer of the heart into the Philokalia, published at Venice in 1782 — the classic anthology of the Jesus-Prayer tradition.
An anonymous Russian account, The Way of a Pilgrim, tells of a wanderer who learns to pray the Jesus Prayer without ceasing; first printed at Kazan in 1884, it carries the prayer into the modern world and, through later translations, to the West.
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.