Isaiah 9:2. The people who walked in darkness have seen a great light.

Matthew (4:16) cites this text with reference to Christs specific sojourn in Capernaum and Galilee not for the purpose of establishing and strengthening faith but only for the purpose of encouragement. The apostles and evangelists are much accustomed to doing this.

People. So then the people of the whole world, Jews as well as Gentiles, were in darkness, that is, in error, unrighteousness, notions, a false understanding of the Law, etc. Light is the Gospel, the gift of the Holy Spirit. It is common for Scriptures to repeat and double the same thing, as is done here, for the purpose of emphasis.

v. 3 Thou hast multiplied the nation, Thou hast not increased its joy. Here is pictured the fruit and power of this light which is propagated from day to day, not satisfied with the corner where the Jews live but spread abroad among the nations throughout the world, a thing that irks the Jews. In Deut. 32:21 we read: “I will provoke them with a foolish nation.” The Jews, who think that they alone should be God’s people, interpret this passage in a distorted way, as if the Gentiles, however numerous, would not come to enjoy God nor rejoice in Him.³ But this is the true meaning: Many nations are received into the kingdom of God; this makes the Jews sick, by this they are provoked to anger, envy, zeal, and a spirit of stupor (cf. Rom. 11:8). This is what it means to lessen their joy” (Luther’s Works, vol. 16, p.97).

Isaiah 7:14. Therefore the Lord Himself will give you a sign, …. But since he{Ahaz} now resists the Word of God and refuses a sign, how can his faith be strengthened? Therefore the prophet speaks of a sign to come, against which they will dash, just as the sign of Jonah was given to the Jews (cf. Matt. 12:39), and those who refuse to believe will perish. Nevertheless, it is a sign of lifting up and building up and strengthening for those who believe (Matt. 12:39; 16:4). And this is the summary of this chapter until the end, because he says that this prediction is already in the process of fulfillment in these unbelievers. עַלְמָה, a young woman capable of giving birth, for an old woman can be a virgin too, but she is not called עַלְמָה.

She shalt conceive. In Hebrew it is “has conceived,” and that is the indication of a miracle; it is as if the prophet were already seeing it. Again, since he says that it is God’s sign, it is necessary that that conception and birth be in a different manner than is commonly and naturally the ease, for it would not be a sign if one Who today is a virgin would become pregnant after a half year. Therefore she has to be both a virgin and with child. Matthew 1:21 f. clearly explains this.

Immanuel. This describes what kind of person it will be. This is not a proper name. He is indeed the Son of a virgin, and yet He is “God with us,” therefore God and man.

15. He shall eat curds and honey. This is a description of His childhood and humanity. As He is said to be born as a true human being, so He will be reared in a true human fashion” (Luther’s Works, vol. 16, p.84).

“²⁴ Thus we have, in all, five parts {Ten Commandments, Apostles’ Creed, Lord’s Prayer, Baptism and Lord’s Supper} covering the whole of Christian doctrine, which we should constantly teach and require young people to recite word for word. Do not assume that they will learn and retain this teaching from sermons alone. ²⁵ When these parts have been well learned, you may assign them also some Psalms and some hymns, based on these subjects, to supplement and confirm their knowledge. Thus our youth will be led into the Scriptures so they make progress daily.

²⁶ However, it is not enough for them simply to learn and repeat these parts verbatim. The young people should also attend preaching, especially at the time designated for the Catechism, so that they may hear it explained and may learn the meaning of every part. Then they will also be able to repeat what they have heard and give a good, correct answer when they are questioned, and thus the preaching will not be without benefit and fruit. ²⁷ The reason we take such care to preach on the Catechism frequently is to impress it upon our youth, not in a lofty and learned manner but briefly and very simply, so that it may penetrate deeply into their minds and remain fixed in their memories. ²⁸ Now we shall take up the above-mentioned parts one by one and in the plainest possible manner say about them as much as is necessary” (Shorter Preface of Large Catechism -Tappert, p. 364-5).

¹⁵ These {Ten Commandments, Apostles’ Creed and Lord’s Prayer} are the most necessary arts of Christian instruction. We should learn to repeat them word for word. ¹⁶ Our children should be taught the habit of reciting them daily when they rise in the morning, when they go to their meals, and they go to bed at night; until they repeat them they should not be given anything to eat or drink. ¹⁷ Every father has the same duty to his household; he should dismiss man-servants and maid-servants if they do not know these things and are unwilling to learn them. ¹⁸ Under no circumstances should a person be tolerated if he is so rude and unruly that he refuses to learn these three parts in which everything contained in Scripture is comprehended in short, plain, and simple terms, ¹⁹ for the dear fathers or apostles, whoever they were, have thus summed up the doctrine, life, wisdom, and learning which constitute the Christian’s conversation, conduct and concern.

²⁰ When these three parts are understood, we ought also to know what to say about the sacraments which Christ himself instituted. Baptism and the holy Body and Blood of Christ, according to the texts of Matthew and Mark at the end of their Gospels where they describe how Christ said farewell to his disciples and sent them forth. (Shorter Preface of Large Catechism -Tappert, p. 363-364).

¹ This sermon has been undertaken for the instruction of children and uneducated people. Hence from ancient times it has been called in Greek, a “catechism” — that is, instruction for children. ² Its contents represent the minimum of knowledge required of a Christian. Whoever does not possess it should not be reckoned among Christians nor admitted to a sacrament,² just as a craftsman who does not know the rules and practices of his craft is rejected and considered incompetent. ³ For this reason young people should be thoroughly instructed in the various parts of the Catechism or children’s sermons and diligently drilled in their practice.

⁴ Therefore, it is the duty of every head of a household to examine his children and servants at least once a week and ascertain what they have learned of it, and if they do not know it, to keep them faithfully at it. ⁵ I well remember the time when there were old people who were so ignorant that they knew nothing of these things — indeed, even now we find them daily — yet they come to Baptism and the Sacrament of the Altar and exercise all the rights of Christians, although those who come to the sacrament ought to know more and have a fuller understanding of all Christian doctrine than children and beginners at school. ⁶ As for the common people, however, we should be satisfied if they learned the three parts which have been heritage of Christendom from ancient times, though they were rarely taught and treated correctly, so that all who wish to be Christians in fact as well as in name, both young and old, may be well-trained in them and familiar with them. (Shorter Preface of Large Catechism -Tappert, p. 362).