Albert Barnes Commentary Job 12:8

"Or speak to the earth, and it shall teach thee; And the fishes of the sea shall declare unto thee." — Job 12:8 (ASV)

Or speak to the earth, and it shall teach thee – Perhaps this appeal to the earth may mean, as Stuhlman supposes, that the same thing is shown in the productions of the earth, as in the case of fierce animals. Noxious weeds and useless plants are more thriving than the plants that are useful, and the growth of poisonous or annoying things on the earth illustrates the same thing as the dealings of God with people – namely, that His dealings are not in accordance with the real nature of objects.

And the fishes of the sea – The same thing is manifested in the sea, where the mighty prey upon the feeble, and the fierce and the ferocious overcome the defenseless. The sentiment is that a great principle pervades all things: that the ferocious, the strong, and the wicked are often prospered, while the weak, the defenseless, the innocent, and the pious are subject to calamities, and that God does not apportion His dealings to the exact character of His creatures. Undoubtedly, Job was right in this. And this general principle might be seen then, as now, to pervade the world.