Today's first reading is often heard on Marian feast days. Today being not a Marian feast day, but a Marian day of Advent, it is paired (as usual) with the Annunciation story. I have to admit, though, I get a little tired of it.
It's the story of King Ahaz, facing invasions from neighboring chieftans. Ahaz is sending ambassadors to create alliances who will help him resist the invaders, while God is telling him to have a little faith. God even offers to send Ahaz a sign, any sign he wants, as proof that God is with his Chosen People to protect them. But Ahaz says, "Not me! I'm not going to ask for a sign! That would be tempting God!" (As if Ahaz' crafting strategic alliances with Assyria was really a sign of his great faith in God.) Isn't it funny the way we can maneuver to maintain appearances of faith, while working frantically to make things work out on our own terms? That's what I got from Ahaz today.
In the end, God devised a sign of his own. Ahaz would get an heir, and we would get a tantalizing hint that this heir was, himself, a "sign" that God would be with his people: that God would be Emmanuel.