Matthew connects the prophecy of the coming Messiah, about 700 years prior (Isaiah 7:14), to Joseph’sencounter with an angel in a dream. Originally, Isaiah spoke this prophecy to King Ahaz, to encourage him to trust in the Lord’s deliverance for Judah. But the overwhelming Assyrian empire was more real to Ahaz than God was. Though King Ahaz was faithless towards God, God was still faithful in delivering Judah. This very prophecy of the virgin birth, which is unfolding in Mary’s womb, is now brought to light by an angel in Joseph's dream. Unlike King Ahaz, Joseph is compelled by God’s command.