For Jacob my servant's sake. This second motive is, in a certain sense, the main one. Cyrus is raised up, especially, to perform God's pleasure with respect to Judah and Jerusalem (Isaiah 44:26-28). Jacob, his Church, is more important in God's eyes than any individual.
No doubt his Church is maintained, in part, that it may be "a light to lighten the Gentiles;" but it is not maintained solely: or even mainly, for this end. Its welfare is an end in itself, and would be sought by God apart from any further consequence.
Israel mine elect (comp. Isaiah 41:8; Isaiah 44:1). I have surnamed thee; i.e. "given thee designations of honour," e.g. "my anointed" (Isaiah 45:1); "my shepherd" (Isaiah 44:28); "he who shall do all my pleasure" (Isaiah 44:28).
Though thou hast not known me; rather, though thou didst not know me. Cyrus's honours, his titles, his mention by name, etc; were accumulated upon him before his birth, when he knew nothing of God, when, therefore, he had in no way merited them.
Thus all was done, not for his sake, but lot the sake of Israel.