“The word mercy in English is the translation of the Greek word eleos. This word has the same ultimate root as the old Greek word for oil, or more precisely, olive oil; a substance which was used extensively as a soothing agent for bruises and minor wounds. The oil was poured onto the wound and gently massaged in, thus soothing, comforting and making whole the injured part. The Hebrew word which is also translated as eleos and mercy is hesed, and means steadfast love. The Greek words for ‘Lord, have mercy,’ are ‘Kyrie, eleison’ that is to say, ‘Lord, soothe me, comfort me, take away my pain, show me your steadfast love.’ Thus mercy… refer[s]… to the infinite loving-kindness of God, and his compassion for his suffering children! It is in this sense that we pray ‘Lord, have mercy…'”
-from the book Orthodox Worship by Benjamin D. Williams and Harold B. Anstall
Painting “Kyrie Eleison” by Soichi Watanabe