First reading, Isaiah 7:10-14
10 Yahweh spoke to Ahaz again and said:
11 Ask Yahweh your God for a sign, either in the depths of Sheol or in the heights above.
12 But Ahaz said, ‘I will not ask. I will not put Yahweh to the test.’
13 He then said: Listen now, House of David: are you not satisfied with trying human patience that you should try my God’s patience too?
14 The Lord will give you a sign in any case: It is this: the young woman is with child and will give birth to a son whom she will call Immanuel.
Second reading, Romans 1:1-7
1 From Paul, a servant of Christ Jesus, called to be an apostle,
2 set apart for the service of the gospel that God promised long ago through his prophets in the holy scriptures.
3 This is the gospel concerning his Son who, in terms of human nature
4 was born a descendant of David and who, in terms of the Spirit and of holiness, was designated Son of God in power by resurrection from the dead: Jesus Christ, our Lord,
5 through whom we have received grace and our apostolic mission of winning the obedience of faith among all the nations for the honour of his name.
6 You are among these, and by his call you belong to Jesus Christ.
7 To you all, God’s beloved in Rome, called to be his holy people. Grace and peace from God our Father and the Lord Jesus Christ.
Gospel, Matthew 1:18-24
18 This is how Jesus Christ came to be born. His mother Mary was betrothed to Joseph; but before they came to live together she was found to be with child through the Holy Spirit.
19 Her husband Joseph, being an upright man and wanting to spare her disgrace, decided to divorce her informally.
20 He had made up his mind to do this when suddenly the angel of the Lord appeared to him in a dream and said, ‘Joseph son of David, do not be afraid to take Mary home as your wife, because she has conceived what is in her by the Holy Spirit.
21 She will give birth to a son and you must name him Jesus, because he is the one who is to save his people from their sins.’
22 Now all this took place to fulfill what the Lord had spoken through the prophet:
23 Look! the virgin is with child and will give birth to a son whom they will call Immanuel, a name which means ‘God-is-with-us’.
24 When Joseph woke up he did what the angel of the Lord had told him to do: he took his wife to his home;