Isaiah said, “Listen, house of David! Is it not enough for you to try the patience of men? Will you also try the patience of my God? Therefore, the Lord himself will give you a sign: See, the virgin will conceive, have a son, and name him Immanuel.
The prophet Isaiah was sent compel King Ahaz to trust God to protect the Southern Kingdom of Judah from the Northern Alliance. God graciously offered King Ahaz proof of His intent to destroy the impending threat, but King Ahaz refused to believe. Despite this, God instructed Isaiah to give him a sign. That sign would be the miraculous conception and birth of a baby boy. More than that, the sign is meant to deliver a message, which is encapsulated in the name of the child; Immanuel. God would be with the people of God. They need not fear the enemies to the north, King Ahaz does not need the help of the Assyrian army; God is with them.
This promise finds its ultimate and most obvious fulfillment in the miraculous conception and birth of Jesus. The Evangelist Matthew uses this verse to demonstrate that Isaiah was pointing us to Jesus; the Son of God who was conceived by the Holy Spirit in the womb of a virgin, Mary. While the manner of Jesus conception has incredible implications; the greater thought from Isaiah is the Incarnation itself. God was with His people in a new way. He was physically Immanuel. The God of creation had humbled himself to become one of the created. He had set aside His infinite glory and confined it to the body of a poor tradesman.
Take time today to meditate on God Incarnate. Consider and contemplate the significance of our God being in the flesh. (For example, access to God is not limited to those who understand ancient Hebrew and worship on a particular hill, being in the flesh, God is revealed to all men.) Do we need to fear any enemies if our God can stand for us and fight? Do we need to succumb to temptation when we have an Intercessor who has overcome the same temptations? He is with us, both in Spirit and flesh.