Isaiah’s prophecy is immense and Judah is small. In Isaiah 57:15 the high and lofty One dwells with the contrite and humble. Judah’s sin fills 1:1-8, God’s surprising grace answers it in 1:9, and Isaiah turns again and again to the figure of a child.
Christ’s birth reaches back to the patriarchs, where Jacob’s Joseph gives way to Judah. The virgin birth shows that Judah could never produce the promised king by his own power. Matthew’s Joseph accepts that in humility.
The southern kingdom’s wicked kings run remarkably parallel to the north’s, and Hezekiah’s reign pictures the suffering servant to come. Both kingdoms share spiritual wickedness as well as political failure.