Isaiah 41:8

But thou, Israel, art 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 to that which could not aid them. But those who trusted in him were safe. For their protection he had raised up Cyrus, for this purpose he had subdued the nations before him. God now expresses to them the assurance that though the nations should be destroyed, yet that he had 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 denote bondage or slavery, but to denote that they had been engaged in his service, and that he regarded them as subject to his laws, and as 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. This most honorable appellation he deserved by a life of devoted piety, and by habitually submitting himself to the will of God. The idea in this verse is, that as they were the descendants of his friend, God deemed himself bound to protect and deliver them according to his gracious promises; and this is one of the many instances where the divine favor is manifested to descendants in consequence of the piety and prayers of their ancestors.