The oldest known copy of the Book of Isaiah is one of the scrolls that became known as the dead sea scrolls. One of several ancient copies of Isaiah that have been found, it is complete, yet it’s missing passages mentioned in other ancient copies.
Given that all of the copies vary, it is unreasonable to believe any of them recorded what god said.
Most likely written several hundred years before Christ was born, the Book of Isaiah was written at a time when god seemed to have a lot to say.
But flash forward 2000 years, when there are ways to accurately record and distribute one’s message around the world, god has been incredibly silent.
Just think how much better the world would be if god got on his global PA system and announced that the Jews and the Palestines should stop killing each other in his name, and instead just live peacefully with their neighbors.
The utter silence from god on the innocent slaughter of thousands of lives in just the most recent dispute, condemns him to being a myth.