Lo, their good is not in their hand; i.e. their prosperity is not in their own power, not the result of their own efforts. God's providence is, at least, one element in it, since he exalts men and abases them, he casteth down and lifteth up.
Hence it would seem to follow that they are his favourites. Shall Job therefore cast in his lot with them? No, he says, a thousand times, No! The counsel of the wicked is far from me; or better, be the counsel of the wicked far from me!
I will have nothing to do with it. I will cling to God. I will maintain my integrity. Satan had charged Job with serving God for the sake of temporal reward. Job had disproved the charge by still clinging to God, notwithstanding all his afflictions.
Now he goes further, and declines to throw in his lot with the wicked, even although it should appear that the balance of prosperity is with them.