And thou sayest, How doth God know? - That is, it "follows" from what you have said; or the opinion which you have advanced is "the same" as if you had affirmed this. How common it is to charge a man with holding what we "infer," from something which he has advanced, he must hold, and then to proceed to argue "as if" he actually held that. The philosophy of this is plain. He advances a certain opinion. "We" infer at once that he can hold that only on certain grounds, or that if he holds that he must hold something else also. We can see that if "we" held that opinion, we should also, for the sake of consistency, be compelled to hold something which seems to follow from it, and we cannot see how this can be avoided, and we at once charge him with holding it. But the truth may be, that "he" has not seen that such consequences follow, or that he has some other way of accounting for the fact than we have; or that he may hold to the fact and yet deny wholly the consequences which legitimately follow from it. Now we have a right to show him "by argument" that his opinions, if he would follow them out, would lead to dangerous consequences, but we have a right to charge him with holding only what he "professes" to hold. He is not answerable for our inferences; and we have no right to charge them on him as being his real opinions. Every man has a right to avow what he actually believes, and to be regarded as holding that, and that only.
How doth God know? - That is, How can one so exalted see what is done on the distant earth, and reward and punish people according to their deserts? This opinion was actually held by many of the ancients. It was supposed that the supreme God did not condescend to attend to the affairs of mortals, but had committed the government of the earth to inferior beings. This was the foundation of the Gnostic philosophy, which prevailed so much in the East in the early ages of the Christian church. Milton puts a similar sentiment into the mouth of Eve in her reflections after she had eaten the forbidden fruit:
And I, perhaps, am secret: heaven is high,
High and remote from thence to see distinct
Each thing on earth; and other care perhaps
May have diverted from continual watch
Our great Forbidder, safe with all his spies about him.
Paradise Lost, B. ix.
Can he judge through the dark cloud? - Can he look down through the clouds which interpose between man and him? Eliphaz could not see how Job could maintain his opinions without holding that this was impossible for God. He could see no other reason why God did not punish the wicked than because "he did not see them," and he, therefore, charges this opinion on Job.

And thou sayest, How doth God (i) know? can he judge through the dark cloud?
(i) He reproves Job, as though he denied God's providence and that he could not see the things that were done in this world.

And thou sayest, how doth God know?.... What is done on earth, the works of the children of men, their sinful actions, when he dwells at such a distance, and so remote from the earth, as the height of the stars, and highest heavens, be; not that Job said this expressly with his lips, but in his heart; Eliphaz imagined and supposed that such was the reasoning of his mind; it was an invidious consequence he had drawn from what Job had said concerning the afflictions of the godly, and the prosperity of the wicked; which he interpreted as a denial of the providence of God, as if he had no regard to human affairs, but things took place in a very disorderly and confused way, without any regard to right or wrong; and he concluded that Job was led into these sentiments by the consideration of the distance of God from the earth; that, dwelling in the highest heavens, he could not and did not see what was done here, and therefore men might commit all manner of sin with impunity; that their sins would never be taken notice of, or they be called to an account for them; which are the very language and sentiments of the most abandoned of men, see Psalm 10:11;
can he judge through the dark clouds? if he cannot see and know what is done, he cannot judge of it, whether it is good or bad, and so can neither justify nor condemn an action. By "the dark cloud" is not meant the matter, or corporeal mass, with which man is covered, as a Jewish commentator (x) interprets it; rather the cloudy air, or atmosphere around us; or that thick darkness in which Jehovah dwells, clouds and darkness being around him, Psalm 97:2; but all this hinders not his sight of things done here below; what is thick darkness to us is pure light to him, in which also he is said to dwell, and with which he covers himself as with a garment; and the darkness and the light are both alike to him, he can see and judge through the one as well as the other.
(x) Peritzol.

Rather, And yet thou sayest, God does not concern Himself with ("know") human affairs (Psalm 73:11).