23“Behold, the virgin shall be with child,
and shall give birth to a son.
They shall call his name Immanuel,”
which is, being interpreted, “God with us.”
24Joseph arose from his sleep, and did as the angel of the Lord commanded him, and took his wife to himself; 25and didn’t know her sexually until she had given birth to her firstborn son. He named him Jesus.Matthew begins his gospel with the "book of the genealogy of Jesus the Messiah." The heading is likely referring to the entire Gospel, even thought the genealogy is connected to it, and the word genealogy should be taken similar to the family histories (genealogy) given by Moses in the book of Genesis (Gen. 6:9; 10:1; 11:10, 27; 25:12, 19; 36:1, 9; 37:2). This is argued, rightly I believe, by W. Davies and Allison, as given by David Turner (BECNT Mt, 2008):
W. Davies and Allison (1988: 150) argue from the LXX usage of the expression βίβλος γενέσεως (biblos geneseōs, Gen. 2:4; 5:1) that this is the title for Matthew’s entire book. They point out that the LXX most frequently uses a different formula, “these are the generations” (αὗται αἱ γενέσεις, hautai hai geneseis), to introduce genealogies (e.g., Gen. 6:9; 10:1; 11:10, 27; 25:12, 19; 36:1, 9; 37:2; Num. 3:1), and that the term βίβλος most naturally refers to a “book,” not merely a portion of it. (W. Davies and Allison 1988: 153; cf. Allison 2005b: 157–62).
Genealogies were important to the Jews because they connected them to their people, provided evidence of what tribe to which a person belonged. Matthew's genealogy demonstrates that Jesus was legally an heir to the throne of David (though see study of the curse of Jeconiah below, Matt 1:11).