God's promise to Israel facing exile uses imagery of the two most dangerous elements - water and fire - representing overwhelming difficulties. "When" (not "if") acknowledges trials are certain. "Pass through" indicates temporary duration, not permanent residence. The key promise: "I will be with you" - God's presence, not absence of trials, is our security.
Historical examples include Israel crossing the Red Sea and Shadrach, Meshach, and Abednego in the fiery furnace (BibleHub Commentaries).
