Kyrie eleison. Kyrie eleison. Kyrie eleison.

Scripture References:
st. = Matt. 20:30, Ps. 51:1, Ps. 57:1

The Kyrie translates into English as follows:

Kyrie eleison; Lard, have mercy;
Christe eleison; Christ, have mercy;
Kyrie eleison. Lard, have mercy.

This ritual song dates from early Greek (Eastern) Christian liturgies and has retained its Greek text in the Latin (Western) rite. In the Eastern tradition the Kyrie is still used in its initial capacity, as a response in litanies. By the end of the eighth century in the Roman (Western) church, the Kyrie was used as a separate song, often in a nine-fold form–a three-time repetition of its three lines, in which the priest uttered the first line, the congregation or (more likely) a choir responded with the second, and the priest responded with the third. The Kyrie became part of the Ordinary (the unvarying parts) of the Roman Catholic Mass, chanted at the very beginning of the service.

Some liturgies of the Reformation continued to use the Kyrie in connection with confession of sin or with the reading of the Ten Commandments. Like other ancient biblical and liturgical expressions (such as "amen," "alleluia," "hosanna," "maranatha"), the Kvrie is a prayer that ties us to Christians from all times and places.

Liturgical Use:
As a sung prayer for mercy in the service of confession and forgiveness; as part of a litany, sung after each petition (as in the oldest traditions); as a frame around spoken prayers.

--Psalter Hymnal Handbook