What does Isaiah 7:6 mean?
The allied kings of Israel and Syria have brought their armies south to Judah with a specific plan. They have not come just to conquer Judah and take its territory for themselves (Isaiah 7:5). They have come to kill King Ahaz and put a man of their choosing on his throne. This man is referred to as "the son of Tabeel."It's unclear who the son of Tabeel was. But it is clear why these two kings want him in place as Judah's king. These two nations don't want to have to worry about fighting Judah when the Assyrians arrive from the east to attack them. They want to guarantee that Judah will have their back. They're afraid that Ahaz will stand with the Assyrians against them.
To accomplish this plan, the kings of Syria and Israel have already killed or captured tens of thousands of Ahaz's people throughout Judah (2 Chronicles 28). Now they are making their way to Jerusalem to take the walled city and plant their king in it (Isaiah 7:1). The Lord, though, is telling Ahaz to calm down and not to worry. These two kings will soon be gone (Isaiah 7:4).