By St. Isidore of Seville
Blessed Isaiah, the son of Amos, whose name is translated "Savior of the Lord," born from the tribe of Judah, noble in birth, honored and distinguished among all the prophets, prophesied under four kings of Judah who succeeded and were descended one from the other, Uzziah, Jotham, Ahaz, and in the end Hezekiah. He prophesied about Judah and Jerusalem and Israel and about Babylon and Philistia, Moab and Damascus, also Egypt and the Desert of the Sea, Idumea and Arabia, the Valley of Death and Tyre, and the land of the Negev. He met his end, however, under Manasseh, king of Judah, son of Hezekiah. Because Isaiah regularly censured Manasseh for his abominations before the Lord in Jerusalem, he was slain by being cut in half with a saw by Manasseh from his head down through his middle (Heb 11:37). Isaiah earned a double honor, the office of prophet and martyr. He was buried under the oak Rogel next to the waterfall that Hezekiah, king of Judah, had set up, when a dam was constructed with earth and dust.
Among the prophets Isaiah is certainly most revered because he narrated all the deeds of Christ in order and most fully, and he published in his own book very many clear testimonies of what was revealed to him by the Lord in the spirit of prophecy.
That Christ Was Born from the Stock of David
Isaiah foretold that Christ would be born according to the flesh from the seed of David, saying: A branch (virga) will come forth from the root of Jesse. Mary the Virgin (virgo) was born from the stock of David; and a flower will arise from his root (11:1). This refers to our Lord Jesus Christ, who was brought forth from the flesh from Mary. And the Spirit of the Lord will rest upon him, the Spirit of wisdom and understanding, the Spirit of counsel and might, the Spirit of knowledge and piety, and the Spirit will fill him with the fear of the Lord (11:2). Why are such great gifts of the Spirit proclaimed by God concerning him? Because the Holy Spirit does not dwell to the same measure in him as in us, but entirely, that is, in the fullness of divinity and grace. He is the one who judges not according to the vision of the eyes and hearing of the ears, for justice is the girdle of his limbs, and faith the girdle of his affections (11:3-5).
That Christ Was Born of a Virgin
The holy Isaiah in ancient times foretold his birth from the Virgin in this way: And the Lord added that he speak to Ahaz, saying: Seek for yourself a sign from the Lord your God in the depth of the underworld or in the height above. And he said: Hear, therefore, O house of David, that is, nation of David. His words were quite rightly addressed to the house of David from whose stock, that is, from Mary and from the Holy Spirit, Christ would be born. And he added: On account of this the Lord himself will give you a sign: Behold, a virgin will conceive in her womb and bear a son, and you will call his name Emmanuel... (7:10-14). Emmanuel is Hebrew for the Latin Deus nobiscum, that is, "God with us." The one whom the Virgin bore is named "God with us."
That Christ Was Born from a Virgin without Intercourse with a Man
The same prophet Isaiah says elsewhere that Christ was not born by male seed, but of a virgin: Let the heavens drop down from above, and let the clouds rain justice; let the earth be opened and let it sprout forth a savior, and let justice arise at the same time; I the Lord created him (45:8). The heavens, that is, the clouds, are the prophets, through whom Christ's coming was prophesied. Mary is the earth who bore him, not, however, by intercourse because the Lord alone brought him into being without the mingling of the seed of a man. Speaking in the person of the Father, Isaiah said: Lo, I send among the foundations of Zion a Stone, approved, a precious, choice cornerstone, and he who will have believed on him will not be confounded... (28:16).
That God Was Made Flesh and Became a Man
The prophet Isaiah proclaims that the Lord would be born in the flesh: A child, he says, has been born to us, a Son has been given to us. And the government is upon his shoulders; and his name will be called Marvelous, Counselor, God, Mighty, Father of the World to Come, the Prince of Peace. His empire will be increased, and there will be no end to his peace (9:6-7). The child surely is Christ, because he was born a man for us.... Moreover, A son has been given to us: Whose son is this except the son of God? His government upon his shoulders, that is, because he himself first carried the cross on his shoulders. Pilate wrote the inscription of "king" on the cross over his shoulders and head: Iesus Nazarenus Rex Iudeorum: "Jesus of Nazareth, King of the Jews." His first name is Marvelous; second Counselor; third God; fourth Mighty; fifth Prince of Peace; sixth Father of the World to Come. Behold, God was born a child.
That Christ the Lord Did Wonders and Marvelous Deeds
The healings and marvelous deeds that Christ worked in the world were written down in advance long ago through the prophet Isaiah when he declared: Behold, our God, he himself will come and save us. Then shall the eyes of the blind be opened, and the ears of the deaf will hear. Then shall the lame man leap like a deer, and the tongue of the dumb will be clear (35:5-6). Likewise, concerning the same thing Isaiah says: The Spirit of the Lord is upon me, because he anointed me; he sent me to the meek in order that I might heal the contrite in heart, announcing that he proclaims redemption to the captive and restores light to the blind (61:1). And again Isaiah says: For in the strength of his virtue he stirred up the dead with his voice (unknown source). To be sure, many saints and prophets did wonders; yet none of them brought the dead back to life except by the word of the Lord....
That Christ Suffered and That He Was Hanged on the Wood of the Cross
Isaiah declared that the Son of God would come to suffer when he said: Who is that man who comes from Edom, with dyed garments from Bozrah? He is beautiful in his robe, walking in the multitude of his strength. I am he who speaks justice, and I am a defender in order to save. Why then are your clothing and vestments red just like the clothing of those who tread in a winepress? I treaded the winepress alone, and of the peoples there was none with me (63:1-3). Truly the prophetic Spirit, contemplating God clothed in the flesh and coming to his passion, mentions that he was covered with blood, likening his bloodstained clothing to the clothing of those who tread a winepress. For men climb down from the vat stained bloodied from the redness of wine. This was also prefigured in Genesis in the person of Judah, from whose tribe Christ descended: "He will wash," he says, "his own robe in wine and his own mantle with the blood red juice of a grape" (Gen 49:11), pointing to his flesh as "robe" and "mantle" and to his blood as "wine." The wine is a figure of the mystery of his blood, the blood of his cup.
Likewise in Isaiah it is also written about him: And his government will be upon his shoulders (9:6), that is, he carried the wood of his own cross on his shoulders. He did not say that he had a crown on his head or a scepter in his hand or wore some peculiar clothing, but only the new King, the King of the Ages, Jesus Christ, bore on his shoulder his power and majesty. Isaiah also asserts: Behold, my servant understands and will be exalted and lifted up and will be very lofty (52:13), that is, through the victory of the cross, his royal power will exalt the form of a servant, that is, the flesh, which he had put on.
That He Died Not for His Own Sins but for Ours
The prophet Isaiah says: For the iniquities of his people he was led to death. And also: All we like sheep have gone astray; each and every one has turned to his own way; and the Lord placed on him the iniquities of us all (53:6).
That He Died
The prophet Isaiah also speaks about the death of the Lord: Just as a sheep is led to death, and even as a lamb in the presence of the one shearing it is without a voice, so he did not open his own mouth. By the iniquities of his own people was he led to death (53:7-8).
That Christ Rose from the Dead and Ascended into Heaven
Through the prophet Isaiah Christ announces: Now I shall rise up, says the Lord, now I shall be exalted, and now I shall be lifted up (33:10). A testimony to the resurrection and ascension of Christ is proclaimed as if to say: Now I shall rise up from the dead, now I shall be exalted in the sky, now I shall be lifted up in my kingdom. In another place Isaiah says: Behold, my servant understands and will be exalted and will be elevated and will be very lofty (52:13), which certainly pertains to the ascension to heaven and the glory of his kingdom.
That, After the Ascension of Christ the Lord into the Heavens, the Gift of the Holy Spirit Will Be Poured Forth upon the Apostles and the Faithful
The prophet Isaiah promises: I shall pour forth my Spirit, says the Lord, and my blessing upon your seed, Jacob; and they will sprout forth among the grasses as willows beside flowing waters (44:3-4). Likewise Isaiah says: Let the Spirit be poured forth from on high (32:15). Again he says: When the Spirit of the Lord will have come like a violent river, and will have come to Zion (59:19-20). And again: The Spirit of the Lord, even as a flooding torrent, will come (30:28), that is, the Spirit comes like the great sound of rushing waters.
That Christ Would Send the Apostles to Bear Witness to the Gentiles of the Glory of His Resurrection
The prophet Isaiah speaks out, saying: I come to gather together all nations and tongues. And they will come and see my glory, and I shall place on them a sign — certainly the sign of the cross — and out of those who will have been saved I shall send men to the nations on the sea and into Africa and into Libya, bearing an arrow — that is, the proclamation of the gospel — into Italy, into Greece, and to islands far off and to those who have not heard about me and have not seen my glory; and they will announce my goodness among the nations (66:18-19 Vg.). Here he speaks about the apostles, that they would proclaim the gospel through the whole world. The prophets were not silent about this, and in the Psalms it was foretold: "Into all the earth their sound is gone out, and into the ends of the world their words. There are no languages or dialects in which their voices should not be heard" (Ps 19:3-4).
That the Lord Would Give the Gospel to the Faithful as a New Law
Thus the prophet Isaiah declares: He first says to Zion: Behold, I am present and I shall give good news to Jerusalem (41:27), because surely the Lord came first to Zion and proclaimed the gospel to Jerusalem. And again Isaiah says: the law will go out from Zion, that is, the gospel of the New Covenant; and the word from Jerusalem, that is, the proclamation of the faith; and He will judge the nations and will reprove many peoples from far away (2:3-4), that is, the teaching of the gospel reproves nations believing in Christ for doing unlawful deeds.
That God Presents to the Faithful the Gift of the Grace of Baptism for Indulgence and Remission of Past Misdeeds
The prophet Isaiah promises: You will draw water joyfully from the springs of the Savior; and you will say on that day: We confess to the Lord and invoke his name (12:3-4). Who is that Savior, from whose springs the prophet says you draw water, except Jesus Christ, Savior of the world, who taught that you are cleansed by the water of holy baptism? Again Isaiah urges: All who thirst, come to the waters, and you who do not have silver, hasten, buy, and eat. Come and buy wine and milk without silver or any exchange (55:1).
That the Gentiles Are Converted to Belief in Christ
The prophet Isaiah already had made a prediction about this, saying: The nations will come, and many peoples will come and will say: Come, and let us ascend to the mountain of the Lord, and to the house of the God of Jacob; and he will teach us about his good paths, and we shall walk on his footpaths (2:2-3). Likewise Isaiah says: They sought me, who previously did not ask about me; they found me, who did not seek me. And I said: Behold, I have come to the nation which did not call on my name (65:1). Again Isaiah says: Everyone from all nations will bring a gift to the Lord on horses and on chariots and on litters and on mules and on carriages to my sacred mountain into Jerusalem into the house of the Lord; and I shall take some of them for priests and Levites, says the Lord (66:20-21), that is, the faithful will make pilgrimage to the Lord's tomb.