Fear - Presence Like Fire

The "fear not" in verse 10 is a conclusion, not an opening line. Read the two verses before it and you find the reason already given: you are my servant, I have chosen you, the offspring of Abraham my friend - "I have chosen you and not cast you off."
Heiser treats this passage in the servant material of Isaiah 40-55, where Israel is the corporate servant. And he points out the same pattern a few chapters later: in Isaiah 44:2, "Fear not, O Jacob my servant" comes straight after the one who formed you from the womb - fathering language. The command not to fear is never bare. It always rests on a stated relationship.
Scripture links:
- Isaiah 41:9-10 - "'You are my servant, I have chosen you and not cast you off'; fear not, for I am with you; be not dismayed, for I am your God."
- Isaiah 44:2 - "Fear not, O Jacob my servant" - following the one who formed you from the womb.
You are not told to be brave in a vacuum. You are told who is standing there.