Isaiah 41:10

The scope of these verses is to silence the fears, and encourage the faith, of the servants of God in their distresses. Perhaps it is intended, in the first place, for the support of God's Israel, in captivity; but all that faithfully serve God through patience and comfort of this scripture may have hope. And it is addressed to Israel as a single person, that it might the more easily and readily be accommodated and applied by every Israelite indeed to himself. That is a word of caution, counsel, and comfort, which is so often repeated, Fear thou not; and again (Isa 41:13), Fear not; and (Isa 41:14), "Fear not, thou worm Jacob; fear not the threatenings of the enemy, doubt not the promise of thy God; fear not that thou shalt perish in thy affliction or that the promise of thy deliverance shall fail." It is against the mind of God that his people should be a timorous people. For the suppressing of fear he assures them, I. That they may depend upon his presence with them as their God, and a God all-sufficient for them in the worst of times.

— Matthew Henry's Concise Commentary (public domain)

be not dismayed--literally, anxiously to look at one another in dismay. right hand of my righteousness--that is, My right hand prepared in accordance with My righteousness (faithfulness to My promises) to uphold thee.

— Jamieson-Fausset-Brown Commentary (public domain)