When you pass through the waters, I will be with you; and when you go through the rivers, they will not overwhelm you. When you walk through the fire, you will not be scorched; the flames will not set you ablaze.
The sudden leap from reproach to consolation is itself the message: no merit of Israel's own stands between what it was and what it will be, but God's free grace meeting it. He who created and formed Israel at the beginning will shelter and preserve it through every hostile element and greatest danger, from which escape seems impossible.
AI summary
Commenting on Isaiah 43:1-2
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. (c) By water and fire he means all kinds of trouble and peril.
Waters and rivers and fire mean the afflictions of God's people in general, persecutions from men, temptations of Satan coming like a flood, and every other trial. Though they come upon believers and distress them greatly, they shall not overflow their faith or separate them from the love of God, for He is with them to sympathize, comfort, and deliver.
AI summary