When you pass through the waters, I will be with you;
And through the rivers, they will not overflow you.
When you walk through the fire, you will not be scorched,
Nor will the flame burn you.
The history of ancient Israel was framed by flood and fire – the “flood” of the Exodus from Egypt and the “fire” of the Babylonian exile. Isaiah combines in parallel, poetic fashion these twin themes of exodus and exile that are so central to Israel’s self-understanding.
The “waters” suggest the Red Sea which the LORD parted so that the nation could cross and escape from Egypt (Exodus 14.21-22). Likewise, the “rivers” recall the Jordan River, which the LORD also parted in order for the people to enter Canaan (Joshua 3.14-17). The “fire” reflects the siege fires that burned Jerusalem (2 Kings 25.8-10), and, symbolically, the seventy years that the people of Judah spent in Babylon.
The promise of this passage is simple: The LORD delivers His people! He does not promise life free from adversity but rather deliverance for those who remain faithful in the face of adversity.