Who hath given him a charge over the earth? The argument seems to be that if God had "received a charge," and were in possession of a mere delegated authority, like the subordinate gods of heathen nations, he might have an interest apart from that of those whom he governs, and so be tempted to be unjust; but as he is the Author of all and the sole Ruler of all, his interest must be bound up with the true interests of his creatures, and cannot clash with them.
He can thus never be unjust, since he can have no temptation to be unjust. Or who hath disposed the whole world? rather, Who hath laid upon him the whole world?. Elihu repeats the idea of the previous clause in other words.