But he also said above, “God would not hearken to him, so that he should answer to one of his charges or of a thousand.” How can Job speak so here? “In the bitterness of my soul,” he says. Therefore it is not him who speaks but his bitterness, insofar as the reflections of Job allow us to express what he means. “Would that one were present who should hear the cause between both” not in order to examine his life in detail and to show that he is unjustly suffering. He does not say that actually, as in the previous passages. He has often said that it is “because of his iniquity.” He wants to demonstrate that the persisting oppression overwhelms him. And this is what Isaiah says, “You became angry, and we, we are distraught,” and in another passage, “Why did you lead us astray from your path?” “I fear, [Job] says, lest I fall or capsize; I am afraid to be forced, one day, to blaspheme or to commit suicide.”
Now whensoever the present life has once begun to grow tasteless, and the love of the Creator to become sweet, the soul inflames itself against self, that it may accuse self for the sins, wherein it formerly vindicated itself, being ignorant of the things above. Whence he yet further adds with propriety, I will let my speech go against myself.
He as it were employs his speech in behalf of himself, who tries to defend by excuses the evil things he has done. But he 'lets his speech go against himself,' who begins to accuse himself of that which he has done amiss. Now very frequently even when we commit sin, we go on to try the things we have done. The mind of itself brings what it does to trial; but forasmuch as it does not at all forsake this in the desire, it is ashamed to acknowledge what it has done; but when it now comes down upon the indulgence of the flesh with the whole weight of its judgment, it lifts itself with a bold voice in the acknowledgment of that self-accusing. Whence it is rightly said here, I will let my speech go against myself; in that the resolute mind begins to let loose against itself words of abhorrence, which aforetime from a feeling of shame it kept to itself through weakness. But there be some that confess their sins in explicit words, but yet know nothing how to bewail in confessing them. And they utter things with pleasure, that they ought to bewail. Hence it is further added with propriety; I will speak in the bitterness of my soul.
He that tells his sins abhorring them, must needs likewise 'speak of them in the bitterness of his soul,' that that very bitterness may punish whatsoever the tongue accuses of in the warrant of conscience. But we must bear in mind, that from the pains of penitence, which the mind inflicts upon itself, it derives a certain degree of security; and rises with the greater confidence to meet the inquest of the heavenly Judge, that it may make itself out more thoroughly, and ascertain how each particular is appointed towards, it.
Job earlier proposed that both the innocent and the unjust are assailed by trials in this world, and touched upon one reason for the punishment of the innocent which he could think of, i.e. that the earth, as if forsaken by God, had been exposed to the almost evil will of an iniquitous power which punishes the innocent at will. He showed that this explanation was not true because there was something clearly unfitting in that argument. Then he asked who was the one who punishes the innocent and why. He intends now to pursue this question here. Before proceeding to this investigation, however, he shows from what point of view he is speaking. For he is speaking in the person of the afflicted man according to the conceptions which sadness supplies him. So he first speaks about the weariness which he suffers in this life because of the tribulations which is suffering. These render life itself wearisome in proportion to their depth. For although living is enjoyable in itself, living in anguish is wearisome. So he says, "My soul is weary of my life." For just as a man who finds his life enjoyable chooses to live, so a man who finds life burdensome tries to deprive himself of life. For this reason he adds, "I will unleash my eloquence against myself." Something is against someone which is destructive to him. A man therefore speaks against himself when he chooses to be deprived of life. But he clearly says, "I will unleash," for many times a man suffers some disturbances in his heart because of passion either of sorrow, desire, anger or the like, but he still controls all these movements by reason so that he does not express them externally by word. However, when his reason wishes to show what it is suffering internally, it produces the hidden disturbances in words, and then reason is said to unleash eloquence which was previously kept hidden internally. To express this he says, "I will speak from the bitterness of my soul," as if to say: The words which I will reveal externally show internal bitterness, giving us to understand that he speaks in the persona of the bitter man.
[AD 407] John Chrysostom on Job 10:1