Final cause; end; purpose; or rather the purpose of obtaining. I open a window for the sake of air, that is, to obtain it, for the purpose of obtaining air. I read for the sake of instruction, that is, to obtain it. Sake then signifies primarily effort to obtain, and secondarily purpose of obtaining. The hero fights for the sake of glory; men labor for the sake of subsistence or wealth.

Account; regard to any person or thing. I will not again curse the ground any more for man’s sake. Genesis 8:21. Save me for thy mercies’ sake. Psalm 6:4.