Suffer me that I may speak - Allow me to speak without interruption, or bear with me while I freely express my sentiments - it is all that I now ask.
And after that I have spoken, mock on - Resume your reproaches, if you will, when I am done. I ask only the privilege of expressing my thoughts on a very important point, and when that is done, I will allow you to resume your remarks as you have done before, and you may utter your sentiments without interruption. Or it may be, that Job utters this in a kind of triumph, and that he feels that what he was about to say was so important that it would end the "argument;" and that all they could say after that would be mere mockery and reviling. The word rendered "mock on" (לעג lâ‛ag) means, originally, "to stammer, to speak unintelligibly" - then, "to speak in a barbarous or foreign language" - then, "to deride or to mock, to ridicule or insult." The idea is, that they might mock his woes, and torture his feelings as they had done, if they would only allow him to express his sentiments.

Suffer me that I may speak,.... To go on with his discourse, without any interruption, until he had finished it; as he before craves their attention, here he entreats their patience to hear him out, as well as to give him leave to begin; they might by their gestures seem as if they were breaking up and departing; or they raised a tumultuous clamour, to hinder his proceeding to reply; or he might fear, that if he was allowed to speak, they would break in upon him before he had done, as they had already; or "bear me", as several of the Jewish commentators explain the phrase; though what he was going to say might sit heavy upon their minds, and be very burdensome, grating, and uneasy to them; yet he entreats they would endure it patiently, until he had made an end of speaking:
and after that I have spoken, mock on; as they had already, Job 12:4; they had mocked not at his troubles and afflictions, but at his words and arguments in vindication of his innocence; and now all he entreats of them is, that they would admit him to speak once more, and to finish his discourse; and then if they thought fit, or if they could, to go on with their scoffs and derisions of him; if he could but obtain this favour, he should be easy, he should not regard their mockings, but bear them patiently; and he seems to intimate, that he thought he should be able to say such things to them, that would spoil their mocking, and prevent it for the future; so the Greek version renders it, "thou shalt not laugh"; and the words being singular have led many to think, that Zophar, who spoke last, is particularly intended, though it may respect everyone of his friends.

literally, "Begin your mockings" (Job 17:2).

Speak - without interruption. Mock - If I do not defend my cause with solid arguments, go on in your scoffs.