Thomas Aquinas

The word which. Here he begins to reprove their guilt on the part of their conversion; and it is divided into three parts. In the first he reproves them for the guilt they were committing in the worship of idols; in the second, for that which they were committing in the oppression of men: chapter 3, "for behold"; in the third, for the guilt they were committing in the abuse of things: chapter 5, "I will sing to my beloved." The first is divided into two: into the title and the tract. The second is at "and it shall come to pass." And he here places the word at the beginning of the chapter, because the prophecy is especially about the incarnate Word. Amos 3: the Lord will not do a word, unless he shall have revealed his secret to his servants the prophets.

And it shall come to pass. Here he carries out his intention. And it is divided into three parts. In the first he promises the remedy of salvation, lest by the weight of the guilt that follows he should lead them into despair; in the second he shows the guilt's culpability, at "thou hast cast off"; in the third he threatens the scourge of punishment, at "therefore forgive not." Concerning the first, three things are set down: first, the preparation of salvation; second, the conversion of the Gentiles, at "and they shall flow"; third, the calling of the Jews at the end, at "house of Jacob."

Concerning the first, three things are set down. First, the time of salvation: whence he says, "And it shall come to pass." And he joins it to the preceding prophecy, or to that which he heard from the Lord, as Gregory says on the beginning of Ezekiel. "In the last days"; that is, in the time of grace, which is called the last, because no other observance of religion shall succeed it. Matthew, the last chapter: "behold I am with you even to the consummation of the world." Genesis 49: "gather yourselves together, sons of Israel, that I may announce to you the things that shall come to you in the last days."

But it seems that this salvation, which is through the incarnation of the Son of God, ought to have been prepared from the beginning of the human race: because the sooner a disease is met with medicine, the more easily it is cured. To this it must be said that medicine ought to be offered according to the condition of the disease. And because the sin of man was through pride, by which he despised the precepts of God, it was fitting that, in order to receive the medicine of salvation, he should be prepared through humility, so that he might recognize the weakness of his own powers: because neither in the natural law nor in the written law, even when helped, could he provide for himself; and thus he would seek the medicine the more humbly and ardently, the less he found help for himself within himself.

Second, the power of the one saving, when it is said, "the mountain of the house of the Lord," on which the house of the Lord is founded. Ezekiel 40: "he set me down upon a high mountain." Third, the degree of the one saving: "on the top of the mountains," that is, of the greater, "and it shall be raised above the hills," that is, the lesser princes. Below, chapter 52: "behold my servant shall understand, he shall be exalted and lifted up, and shall be exceedingly high."

And they shall flow unto it. Here the conversion of the Gentiles is set down; and concerning this he sets down three things. First, the conversion itself; second, he declares the order of the conversion, at "and the peoples shall go"; third, he promises peace to those converted, at "and he shall judge the nations." He says, therefore, as to the first: "and they shall flow," in which multitude and haste are noted, "all nations," that is, some out of all the nations. Jeremiah 31: "I will bring them through the torrent of waters, in a straight way, and they shall not stumble in it."

The order of the conversion was that through the calling of those who were of the Jews, the Gentiles were converted. And therefore he sets down three things concerning the second: first, those calling; second, the calling itself, at "come"; third, the reason of the order, at "for out of Sion." He says, therefore: "peoples," that is, those who were of the Jews, "many," not all — in which is noted the fewness of the Jews converted with respect to the multitude of the Gentiles — "shall go," believing with the steps of faith, "and shall say." 2 Corinthians 4: "we also believe, for which cause we also speak."

Come. Here the calling is set down. Now they call unto three things: to the eminence of faith — whence he says, "come," by consent, "let us go up" by faith "to the mountain of the Lord," that is, to Christ, "and to the house of the God of Jacob," that is, to the Church. Jeremiah 31: "arise, and let us go up to Sion, to the Lord our God: for thus says the Lord: rejoice with gladness, Jacob." Hebrews 12: "the ascent to mount Sion," etc.

Second, to doctrine, when he says: "he will teach us his ways," that is, the precepts by which one goes to him. Canticles 8: "there thou shalt teach me, and I will give thee a cup of spiced wine, and new wine of my pomegranates."

Third, to obedience: "and we will walk," after him, "in his paths" of counsels. Jeremiah 6: "ask for the old paths, which is the good way, and walk in it."

For out of Sion. Here he sets down the reason of the order, saying: "for out of Sion," not out of mount Sinai, "shall the law go forth," understood spiritually, "and the word of the Lord," that is, the Gospel, "out of Jerusalem," on account of the contemplation of peace: for salvation is of the Jews. John 4. And below, chapter 27: "they who go forth with vigor from Jacob shall flourish, and Israel shall bud."