Israel … my servant (comp. Isaiah 44:1, Isaiah 44:2, Isaiah 44:21; Isaiah 45:4; Isaiah 48:20; Isaiah 49:3-6, etc.). The title characterizes these later chapters, and, while standing no doubt in some special relation to the "Servant of Jehovah" who is the subject of Isaiah 42:1-5; Isaiah 49:5-7, etc; is perhaps mainly selected, and dwelt on, to console Israel in captivity, when servants of the King of Babylon (2 Chronicles 36:20), by the thought that their true Master was God himself, and that to him, and him only, did they really belong.
Jacob whom I have chosen (comp. Isaiah 44:1). (On this "choice," and the love which it implied, see Deuteronomy 7:6-8; Deuteronomy 10:15) Abraham my friend; or, Abraham that loved me. It was the special privilege of Abraham to be known as God's friend (see 2 Chronicles 20:7; James 2:23) among the Hebrews, even as he is among the Arabs to this day.
The "friendship" intended comprised, no doubt, both an active and a passive element, but it is the active element which the word principally enforces. Abraham loved God, and showed his love by his obedience.