What does Matthew 1:2 mean?

Matthew opened his book by declaring that Jesus Christ—meaning Jesus the Messiah—was a son of David and a son of Abraham. It makes sense, then, that he begins his genealogy of Jesus' line with Abraham, the first of God's chosen people (Genesis 12:1–3).

Every Jewish child would have known the names of Israel's three patriarchs from their earliest days. Their stories are all told in the first book of Moses' writings called Genesis. Isaac was the long-awaited child promised by God to Abraham and Sarah (Genesis 21:1–7). Isaac fathered the twins Esau and Jacob, but only Jacob inherited God's covenant promises for Israel (Genesis 25:21–23). Jacob fathered twelve sons by four different women (Genesis 35:23–26). Matthew traces the line of Jesus through Jacob's fourth son Judah.

Jacob's prophecy about his sons and their descendants specifically says that "the scepter shall not depart from Judah, nor the ruler's staff from between his feet" (Genesis 49:10). The writer of Hebrews agrees with Matthew that "it is evident that our Lord was descended from Judah" (Hebrews 7:14).