What does Isaiah 7:16 mean?
This conversation with King Ahaz happened around 735 BC. At this moment, the armies of Syria and Israel were making their way to attack Jerusalem and remove Ahaz from the throne (Isaiah 7:6). The Lord told Ahaz not to worry about this, because it would not be an issue for long (Isaiah 7:7).By the year 733 or 732 BC, the Assyrians had defeated Syria and killed its king, aside from its capital of Samaria. They had also conquered much of Israel. Samaria and the rest of the northern kingdom of Israel would fall as well, by around 721 BC.
This all fits exactly with the miraculous sign Isaiah described to Ahaz (Isaiah 7:14). He has said that young maiden or virgin will soon conceive a son and will call him Immanuel, which means "God with us." Now he says that before that boy knows how to tell evil and from good, the land of those two kings Ahaz dreads will be emptied. When the boy is two or three, both Israel and Syria will cease to be a threat. By the time the boy is 13, both will be completely wiped out. Their people will be deported by the Assyrians and the land sitting empty.
This may sound like the best news Ahaz could have hoped to hear. But Isaiah will reveal in the following verse that the enemy who wipes out Judah's current threat will bring far greater devastation than their current enemies could have brought (Isaiah 7:17).