When the Lord sent Isaiah to Ahaz, he couldn’t have expected much. Ahaz is introduced in 2 Kings as the king of Judah. He did not do what was right in the eyes of the Lord. He even appears to have participated in Canaanite idol worship by sacrificing his son! So, when Isaiah approaches him to have him ask for a sign, I wonder if he felt like Jonah being sent to the Ninevites.
In a sign of false modesty, Ahaz refuses to do as God wishes and will not put the Lord to the test. So, God offers a sign anyway. Through Isaiah he tells Ahaz that the sign will be a virgin who will conceive and bear a son. In the immediate context, the sign was to show Ahaz that he had nothing to fear from the northern kingdom of Israel and its ally Syria. But, this prophecy also foretold another child that doesn’t save from political enemies, but from our sin.
Before Joseph had brought Mary into his house he found she was with child. This must have been incredibly hard. He surely must have been hurt and felt betrayed. Being righteous and not wishing her to be harmed, he was going to divorce her quietly. But, the Lord showed him that Mary had done nothing to deserve being dismissed.
He sent the angel to him in a dream, and the angel uses the very words of the prophet Isaiah “Behold, a virgin shall conceive and bear a son and shall call his name Immanuel”. Joseph likely knew the words, but probably never imagined that they would be applied to his family. He knew that Mary and her baby were special and took her into his home.
And so Ahaz, as a descendant of David rejected the Lord when he came to him and would not ask for a sign. Joseph, also of the house of David, took the sign given to Ahaz into his home. Jesus is the sign given to both Ahaz and Joseph. He is coming back and we also need to prepare to welcome Him. Christmas day is at hand, the incarnation is made present before us. Let us welcome Him as a child. He is coming again in glory to judge the living and the dead, let us prepare for that day. Cast off sin and let the grace of Christ work in you.