John Calvin Commentary Isaiah 41:10

"Fear thou not, for I am with thee; be not dismayed, for I am thy God; I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness." — Isaiah 41:10 (ASV)

Fear not. Since the former doctrine aimed for the people to rely on God, the Prophet concludes from the numerous blessings by which the Lord manifested his love, that the people should not be afraid. And we should carefully observe the reason which he assigns—

For I am with you. This is a solid foundation of confidence, and if it is fixed in our minds, we will be able to stand firm and unshaken against temptations of every kind. In like manner, when we think that God is absent, or doubt whether or not he will be willing to assist us, we are agitated by fear and tossed about amid many storms of distrust. But if we stand firm on this foundation, we will not be overwhelmed by any assaults or tempests. And yet the Prophet does not mean that believers stand so boldly as to be completely free and devoid of all fear; but though they are distressed in mind and in various ways are tempted to distrust, they resist with such steadfastness as to secure the victory. By nature, we are timid and full of distrust, but we must correct that vice by this reflection: “God is present with us, and takes care of our salvation.”

Yet I will assist you. The phrase אף עזרתיך (aph gnazarticha) is rendered by some in the past tense, “Yet I have assisted you;” but I render it in the future tense, “I will assist you.” I translate אף (aph) yet, as it is usually translated in many other passages. Yet it is not inappropriate to translate it even, and accordingly, my readers are free to make their choice. If the past tense of the verb is preferred, it will mean “moreover” or “also.”

With the right hand of my righteousness. Under the word “righteousness,” Scripture includes not only equity, but that fidelity that the Lord manifests in preserving his people; for he gives a display of his righteousness when he faithfully defends his people against the contrivances and various attacks of wicked men. He therefore gives the appellation of “the right hand of righteousness” to that by which he shows that he is faithful and just. Hence we should draw remarkable consolation; for if God has determined to protect and defend his servants, we should not have any terror; because God cannot deny himself (2 Timothy 2:13) or lay aside his righteousness.