Wiktionary
for god's sake
interj. An exclamation showing surprise, impatience, or some other emotion.
Usage examples of "for god's sake".
He was out of training, an old man, for God's sake, and not yet forty.
Half the time, if you really want to know the truth, when I'm horsing around with a girl, I have a helluva lot of trouble just finding what I'm looking for, for God's sake, if you know what I mean.
And in the meantime, if you can sit and talk with me of other things, for God's sake, stay and do so.