There are 2 main stories Christians use from the Old Testament to symbolize God's preservation of them through trials. The Red Sea crossing (which happened BEFORE Isaiah) & Daniel's 3 friends in a fiery furnace (which happened AFTER Isaiah's time). The Bible testifies to its own Divinity.
When thou passest through the waters,
I will be with thee; and through the rivers,
they shall not overflow thee:
when thou walkest through the fire,
thou shalt not be burned;
neither shall the flame kindle upon thee.
Isaiah 43:2