Albert Barnes Commentary Isaiah 41:8

"But thou, Israel, my servant, Jacob whom I have chosen, the seed of Abraham my friend," — Isaiah 41:8 (ASV)

But you, Israel, are my servant - This is an address directly to the Jews, and is designed to show them, in view of the truths which had just been urged, that God was their protector and friend. Those who relied on idols were trusting in what could not help them. But those who trusted in him were safe. For their protection he had raised up Cyrus, and for this purpose he had subdued the nations before him. God now expresses to them the assurance that though the nations should be destroyed, he had nevertheless chosen them, and would remember them and his promise made to Abraham, their illustrious ancestor.

The word ‘servant’ here is used in a mild and gentle sense, not to signify bondage or slavery, but to indicate that they had been engaged in his service, and that he regarded them as subject to his laws and under his protection.

Jacob whom I have chosen - The descendants of Jacob, whom I have selected to be my people. Abraham my friend. Hebrew: ‘Loving me,’ my lover.

Abraham was regarded as the friend of God (see 2 Chronicles 20:7). And he was called the Friend of God (James 2:23). He deserved this most honorable title by a life of devoted piety and by habitually submitting himself to the will of God.

The idea in this verse is that because they were the descendants of his friend, God considered himself bound to protect and deliver them according to his gracious promises. This is one of the many instances where divine favor is shown to descendants as a result of the piety and prayers of their ancestors.