A virgin shall conceive, and bear a son, and shall call His name Immanuel.@Isaiah 7:14

From 14th Century Latin, in Thesaurus Hymnologicus, by Hermann Adalbert Daniel, 1841–55. English translation in the Cowley Carol Book, revised and enlarged edition, compiled by George R. Woodward (London: A. R. Mowbray, 1922), number 3, alt.

Württemberg attributed to Johann Rosenmüller (1615–1684) (🔊 pdf nwc).

Childling of a maiden bright
Life today hath brought to light;
And hath put the prince of night
With his flock of fiends to flight:
Christus natus hodie.

Whoso aught hath done amiss,
And it rue him sore for this,
Mary’s Babe will shrive iwis,
Gentle as a Lamb He is:
Miserere, Domine.

He at Bethlehem was born,
Salem gave Him crown of thorn,
Life of want and death of scorn—
All for love of man forlorn.
Ergo benedicite.

On this Infant may we call,
Born for man in oxen stall;
He vouchsafes us bliss withal
In His everlasting hall.
Cum Maria Virgine.