I have looked at this before, but am greatly informed by the editor of this hymnal, John de Luca, that the text is from the C5 Liturgy of St James – so now you now. This translation is by Gerard Moultrie. Two “descendeth”s in one song is a bit much.
It is set to the moving tune PICARDY, which is here called a French Noel as arranged for the English Hymnal. It is an atypical Christmas song.
It’s a good excuse for a fake organ BIAB backing.
1 Let all mortal flesh keep silence
And with fear and trembling stand;
Ponder nothing earthly minded,
For with blessings in his hand
Christ our God to earth descendeth,
Our full homage to demand.2 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 heav’nly food.3 Rank on rank the host of heaven
Spreads its vanguard on the way,
As the Light of light descendeth
From the realms of endless day,
That the powers of hell may vanish
As the darkness clears away.4 At his feet the six-winged seraphs,
Cherubim with sleepless eye,
Veil their faces to the presence,
As with ceaseless voice they cry:
“Alleluia, alleluia,
alleluia, Lord Most High!”