Alcuin of York — on Rev 7:2-3 (COMMENTARY ON REVELATION)

“And I saw another angel ascending from the rising of the sun, having the sign of the living God; and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea, saying: Hurt not the earth, nor the sea, nor the trees, till we sign the servants of our God in their foreheads. Christ is an angel because we know he announced the joys of the new life to the world, he about whom it is said, angel of great counsel. [Is. 9:6 acc. to LXX, where the verse is number 5.] The ascent from the rising of the sun meant here is the one by which, starting from the Resurrection itself, which sprang up like a new sun, he grew and filled up the whole world, and illuminated it with the evangelical teaching. With that voice he also prevented the noxious power of the four angels from doing harm, and destroyed it in both initiators and subordinates at the same time; whence Nebuchadnezzar also saw a stone cut out of a mountain without hands strike the aforesaid statue on its iron feet and break it in pieces. [Dan. 2:34] By this stone is represented the Lord Jesus Christ, begotten of Jewish stock without conjugal act, who struck the statue on the feet and made it fall, because he reached the extremity of the kingdom of the Romans with the preaching of the Word, and converted the aforesaid kingdoms of the world to rebuild them wholesomely. This same Mediator is said to have the sign of the living God, that is the mystery of the cross. By the fact that he says not "till I sign" but till we sign, he shows that there are in him many people through whom that mystery is being fulfilled. When he says in their foreheads, he indicates the inner forehead, for we smear both side posts with the blood of the Lamb, [Ref. to Ex. 12:5 et seq.] and it is no use for anyone to wear it on the outside if they do not also receive it on the inside, because faith without works is idle. [James 2:20 acc. to the Greek version.]”