Kyrie Eleison Meaning: What "Lord, Have Mercy" Means and Its Biblical Roots

In this session of The Mass Explained, Dr. Brant Pitre traces the Kyrie Eleison — sung or said in the penitential rite near the start of the liturgy — to its scriptural roots: the cry "Lord, have mercy on us" in the Greek Old Testament (Psalm 40; Isaiah 33) and, above all, the two blind men on the road from Jericho who call out to Jesus, "Lord, have mercy on us, Son of David!" (Matthew 20:29–34). He then follows the prayer through the early Church — its place in the fourth-century so-called Clementine Liturgy, Pope St. Gregory the Great's sixth-century defense of the Kyrie, and its medieval development — and unfolds its mystical meaning in St. Augustine (our inner spiritual blindness) and St. Thomas Aquinas (the threefold Kyrie–Christe–Kyrie as a prayer to the Father, the Son, and the Holy Spirit).

Key passages & sources examined: "Lord, have mercy" in the Greek Old Testament (Psalm 40:5; Isaiah 33:2); the healing of the two blind men near Jericho (Matthew 20:29–34); the fourth-century so-called Clementine Liturgy; Pope St. Gregory the Great on the Kyrie (Letters, A.D. 598); Amalar of Metz and the medieval "tropes"; St. Augustine (Sermon 88); and St. Thomas Aquinas on the Kyrie and the Trinity (Summa Theologiae III, q. 83).