Isaiah, Mighty Seer, in Days of Old

Singing the Psalms is an integral part of Christian worship. But we do well to sing other parts of the Bible in our liturgies too. Indeed, there is an ancient tradition of doing so, and some have claimed that the entire Hebrew text of the Old Testament contains musical notations for chanting. In 1526, nine years after he nailed his ninety-five theses to the door of the castle church in Wittenberg, Martin Luther published his Deutsche Messe, or German Mass, which was a reworking of the Latin rite in the German language. Rather than translating directly from Latin, Luther saw fit to elaborate on the songs in the ordinary of the mass, including the Sanctus. In its traditional form, the Sanctus runs as follows:

Sanctus, sanctus, sanctus Dominus Deus Sabaoth! Pleni sunt coeli et terra gloria tua.

Holy, holy, holy Lord God of hosts! Heaven and earth are full of your glory.

Because the Sanctus comes from the words of the seraphim in Isaiah 6 (see also Revelation 4:8), Luther composed a free paraphrase of the first four verses. Although this Scripture paraphrase is not well known outside the Lutheran tradition, here is the best known version in English, apparently a composite of more than one translation:

Isaiah, mighty seer, in days of old
The Lord of all in Spirit did behold
High on a lofty throne, in splendor bright,
With flowing train that filled the Temple quite.
Above the throne were stately seraphim,
Six wings had they, these messengers of Him.
With twain they veiled their faces, as was meet,
With twain in reverent awe they hid their feet,
And with the other twain aloft they soared,
One to the other called and praised the Lord
Holy is God, the Lord of Sabaoth!
Holy is God, the Lord of Sabaoth!
Holy is God, the Lord of Sabaoth!
Behold, His glory filleth all the earth!
The beams and lintels trembled at the cry,
And clouds of smoke enwrapped the throne on high.

 Here is this hymn from Concordia Publishing House's YouTube channel: