Fear not; for I am with you: be not dismayed; for I am your God: I will strengthen you; yea, I will help you; yea, I will uphold you with the right hand of my righteousness.
Read Chapter 41
Eusebius of Caesarea
He adds that he is to strengthen and sustain those undergoing afflictions at the hands of those [who oppose God] with the vision of the goal that awaits them. He encourages with good news of God speaking to you without deceit: “I am the Lord and God, and I strengthen your right arm,” and I say to you, “Do not fear, I will help you.” In the Septuagint, “I will help you, do not fear, you worm Jacob,” does not appear. This one who was after the former people called “chosen” is now called worm through its worm-like subjection to the cities of the unbelieving nations and all of their polytheistic errors. In addition, what is perfect and special in the apostolic preaching will destroy and remove the demonic energies from the depth of human thinking. Indeed, the Savior called himself a worm, saying “I am a worm and no man,” a disgrace among people and an object of their contempt. Since there were only a few who were the Savior’s disciples, there being twelve apostles, therefore the Septuagint...
For to none other than to God does it belong to implant courage in the fearful, saying to the fainthearted, “Fear not, for I am with you, be not dismayed,” as says the psalmist, “Yes, though I walk through the valley of the shadow of death, I will fear no evil, for you are with me.” - "Against Eunomius 2.15"