I reflect on Ahaz, one of Israel’s cruelest kings, a ruler so corrupt that he sacrificed his own son to the god Moloch. When Isaiah confronted him, God offered protection and even invited Ahaz to ask for a sign. Cloaking his distrust in false piety, Ahaz refused. He preferred political alliances over faith in God’s providence. Yet God’s response bypassed the king entirely. Isaiah proclaimed the birth of an Emmanuel-child as the sign that God remained with the people.

The irony is striking. Matthew later drew on this very prophecy—originally addressed to a child-killing king—to interpret the birth of Jesus, the Son of God who would conquer sin and death. Even more ironic is the nature of the sign itself: not power or spectacle, but the utterly ordinary birth of a child. This is God’s pattern. Faced with arrogance and political maneuvering, God works through humility, vulnerability, and the faithful courage of ordinary people.

Matthew reinterprets Isaiah’s prophecy to reveal Emmanuel, God-with-us, and he does so with remarkable restraint. Unlike Luke’s focus on Mary, Matthew highlights Joseph and God’s quiet initiative. With disarming simplicity, he writes that Mary was “found with child through the Holy Spirit.” In those few words, the Incarnation enters history and Joseph is invited into a radically new reality. His yes required relinquishing his home, his security, and his reputation—everything by which identity is usually measured.