O tyred Brynwr pobloedd byd

O tyred, Brynwr
    pobloedd byd,
A dangos D'eni O forwyn ddrud;
  I'r oesoedd boed
      yn syndod byw:
  Fel hyn y gweddai geni Duw.

Fe ddaw fel gwr o'i 'stafell gu -
O'r neuadd freiniol, fawr ei bri -
  Fel cawr o ddyblyg ansawdd Ef,
  Yn dod i redeg gyrfa gref.

Yn gydradd Un â'r
    Tad y'th wnaed,
Tydi mewn gwisg o gnawd a gwaed!
  Cryfha â'th rinwedd Di Dy hun
  Wendidau mawrion marwol ddyn.

Disgleirio'n llachar mae Dy grud:
Y nos a rydd ei golau drud
  A phell uwch dynol eglurhad
  Tywynned ffydd a'i
      lewyrch mad.

O come, Redeemer of the
    peoples of the world,
And show Thy birth of the dear virgin;
  To the ages let them
      live in astonishment:
  As this would befit the birth of God.

He comes as a man from his dear room -
From the royal hall, of great prestige -
  Like a giant of dual nature He,
  Coming to run his strong course.

In degree One with the
    Father art thou made,
Thou in the clothing of flesh and blood!
  Strengthen with Thy own merit
  The great weaknesses of mortal man.

Shining brightly is Thy cradle:
The night which gives its dear light
  And far above human clarification
  Let faith shine and its
      virtuous radiance.

O come, Redeemer
    of the earth,
And manifest thy virgin-birth.
  Let every age in
      wonder fall:
  Such birth befits the God of all.

Proceeding from His chamber free
That royal home of purity
  A giant in twofold substance one,
  Rejoicing now His course to run.

O equal to the
    Father, Thou!
Gird on Thy fleshly mantle now;
  The weakness of our mortal state
  With deathless might invigorate.

Thy cradle here shall glitter bright,
And darkness breathe a newer light
  Where endless faith shall shine serene
  And twilight never
      intervene.

from the Latin
Veni redemptor gentium
St Ambrosius c.339-397