A Hymn I heard in Mass today

Today I was at mass and at the offertory they played my favorite hymn "Let All Mortal Flesh Keep Silence", I was struck at the beauty of it even more than usual since it has been quite awhile since I have heard it. The Words come from the Liturgy of St James in the Fourth Century, translated from Greek and the music comes from a French Carol from around 1906.
If you have ever heard this you must know how amazing it is, especially when sung in chorus. The words itself are so beautiful and when I hear them they cause me to feel the amazing power of God.
Here is a transcript of "Let All Mortal Flesh Keep Silence."
Let all Mortal Flesh Keep Silence,
And with fear and trembling stand;
Ponder nothing earthly minded,
For with blessing in his hand,
Christ our God to earth descendth,
Our full homage to demand.

King of Kings yet born of Mary,
As of old on earth He stood,
Lord of Lords ,in human vesture,
In the body and the blood;
He will give to all the faithful,
His own self for heavenly food.

Rank on rank the hosts of heaven,
Spreads its vanguard on the way,
As the light of lights descending,
From the realms of endless day,
That the powers of hell may vanish,
As the darkness clears away.

At His feet the six winged seraph,
Cherubim with sleepless eye,
Veil their faces to the prescence,
As with ceaseless voice we cry:
Alleluia, Alleluia, Alleluia
Lord most High!
I hope, if you haven't already, you get to hear this someday.