Veni redemptor gentium

"Veni redemptor gentium" (Come, Redeemer of the nations) is a Latin Advent or Christmas hymn by Ambrose in 88 88 iambic dimeter. The hymn is assigned to the Office of Readings for Advent, from December 17 through December 24, in the Liturgy of the Hours.

The later hymn "Veni Creator Spiritus" borrows two lines from the hymn (Infirma nostri corporis — Virtute firmans perpeti). "Veni redemptor gentium" was particularly popular in Germany where Martin Luther translated it into German as "Nun komm, der Heiden Heiland," which then he, or possibly Johann Walter, set as a chorale, based on the original plainchant. Luther adapted the original chant tune separately for each of three other hymns: "Verleih uns Frieden gnädiglich", "Erhalt uns, Herr, bei deinem Wort" and "Gib unserm Fürsten und aller Obrigkeit."

In the mid-nineteenth century, John Mason Neale translated Veni redemptor gentium into English as Come, thou Redeemer of the earth. It is often sung to the tune Puer nobis nascitur by Michael Praetorius.

In 1959, Dom Paul Benoit, OSB adapted the chant melody as the hymn tune CHRISTIAN LOVE, for use with the text "Where Charity and Love Prevail," Omer Westendorf's common metre translation of the Holy Thursday hymn "Ubi caritas."

Latin:
Veni, redemptor gentium;
ostende partum Virginis;
miretur omne saeculum:
talis decet partus Deum.

...
Wikipedia