According to 2 Chronicles 28,
Aram-Damascus, under Rezin, and Israel, under Pekah, attempted to depose Ahaz through an invasion. Judah was being defeated and, according to 2 Chronicles 28, lost 120,000 troops in just one day. Many significant officials were killed, including the king's son Maaseiah. Many others were taken away as slaves.
According to Isaiah 7
Isaiah tells King Ahaz that the invasion will be unsuccessful and tells him to ask God for a sign. Ahaz refuses, claiming he does not want to test God. Isaiah then announces that God himself will choose the sign, etc.
The question:
Prophet Isaiah's visit to Ahaz in Isaiah 7, was it before or after what happened in 2 Chronicles 28- 5:15?
If the visit and prophecy of Emanuel, was before the horrible things that happened in 2 Chronicles 28- 5:15, then how could the prophecy of Emanuel had been a promise of salvation, protection to the house of David, from the danger of the impending invasion of Aram and Ephraim?