King Ahaz refused the invitation of Ephraim and Syria (Aram) to join forces.
They threaten to invade and destroy Judah because of this. (2 Kgs 16:7-9)
Ahaz was afraid and looked to Assyria, who was the superpower of the time for help - seeking an alliance.
God instructed Isaiah to speak to Ahaz:
To not strike an alliance with Assyria
That Yahweh Himself will ensure Judah’s safety and rescue her from the hands of Ephraim and Aram.
But Ahaz did not believe, so Isaiah told him to ask God for a sign; Ahaz refused, citing that it was not right to test God. But in reality, he had already struck an alliance with Assyria and he did not trust God.
