John Calvin Commentary Isaiah 41:13

"For I, Jehovah thy God, will hold thy right hand, saying unto thee, Fear not; I will help thee." — Isaiah 41:13 (ASV)

For I am Jehovah thy God. The Prophet had already shown where the hope of salvation ought to be placed, so that we can hold out against every attack. This means being convinced that God is our God and is on our side. He now lays down the same doctrine, but in different words. Yet the repetition is not superfluous, for we know how easily this doctrine slips out of our minds, even though it is frequently repeated. And this promise, which is so difficult to root in our hearts, could not be commended too highly.

Let us therefore know that we will have a successful outcome in all our struggles, for the Lord is present with us. Whenever we are attacked by any severe struggle, let us learn to look to Him; for if we hesitate and look here and there, we will never enjoy peace of mind.

When he calls himself our God, he not only mentions his power but gives proof of his goodness, which he intends to exercise towards us. For it would not be enough to be convinced of the power of God if we were not equally certain of his love; and even when we are terrified by the mention of his power alone, his goodness is well fitted to give us peace.

Taking hold of thy right hand, and saying to thee. He now speaks about “taking hold of the hand,” and about his voice; for it is of great importance to us to believe the signs which God has given us of his love, and to connect with them the doctrine which assures us of his eternal favor. The word saying is therefore highly emphatic, for we must remain in suspense until the Lord speaks, whose voice alone can remove fear and bring peace. If, then, we desire to have composure of mind and to conquer the troubles that come upon us from various sources, we must pay close attention to his voice, so as never to withdraw our mind from it. For those who refuse to hear this voice of God, or do not hear it attentively, must be miserably tormented by continual doubt and uncertainty.