Till he fill thy mouth with laughing - Until he make thee completely happy. The word rendered "till" (עד ‛ad), is rendered by Dr. Good, "even yet." Noyes, following Houbigant, DeWette, and Michaelis, proposes to change the pointing, and to read עד ‛ôd, instead of עד ‛ad - meaning, "while." The verse is connected with that which follows, and the particle used here evidently means "while," or "even yet" - and the whole passage means, "if you return to God, he will even yet fill you with joy, while those who hate you shall be clothed with shame. God will show you favor, but the dwelling of the wicked shall come to naught." The object of the passage is to induce Job to return to God, with the assurance that if he did, he would show mercy to him, while the wicked should be destroyed.
With rejoicing - Margin, "Shouting for joy." The word used (תרוּעה terû‛âh) is properly that which denotes the clangor of a trumpet, or the shout of victory and triumph.

Till he fill thy mouth with laughing - Perhaps it may be well to translate after Mr. Good "Even yet may he fill thy mouth with laughter!" The two verses may be read as a prayer; and probably they were thus expressed by Bildad, who speaks with less virulence than his predecessor, though with equal positiveness in respect to the grand charge, viz., If thou wert not a sinner of no mean magnitude, God would not have inflicted such unprecedented calamities upon thee. This most exceptionable position, which is so contrary to matter of fact, was founded upon maxims which they derived from the ancients. Surely observation must have, in numberless instances, corrected this mistake. They must have seen many worthless men in high prosperity, and many of the excellent of the earth in deep adversity and affliction; but the opposite was an article of their creed, and all appearances and facts must take its colouring. Job's friends must have been acquainted, at least, with the history of the ancient patriarchs; and most certainly they contained facts of an opposite nature. Righteous Abel was persecuted and murdered by his wicked brother, Cain. Abram was obliged to leave his own country on account of worshipping the true God; so all tradition has said. Jacob was persecuted by his brother Esau; Joseph was sold into slavery by his brothers; Moses was obliged to flee from Egypt, and was variously tried and afflicted, even by his own brethren. Not to mention David, and almost all the prophets. All these were proofs that the best of men were frequently exposed to sore afflictions and heavy calamities; and it is not by the prosperity or adversity of men in this world, that we are to judge of the approbation or disapprobation of God towards them. In every case our Lord's rule is infallible: By their fruits ye shall know them.

Till he fill thy mouth with (m) laughing, and thy lips with rejoicing.
(m) If you are godly, he will give you opportunity to rejoice and if not your affliction will increase.

Till he fill thy mouth with laughing, and thy lips with rejoicing. Directing himself to Job; and suggesting, that if he was a perfect, sincere, and upright man. God would not cast him away utterly, but help him out of his present circumstances, and restore him to prosperity; and not leave him until he had filled his heart with so much joy, that his mouth and lips, being also full of it, should break forth in strong expressions of it, and in the most exulting strains, as if it was a time of jubilee with him; see Psalm 126:2; but Bildad tacitly insinuates that Job was not a perfect and good man but an evil doer, whom God had cast away and would not help; and this he concluded from the distressed circumstances he was now in; which was no rule of judgment, and a very unfair way of reasoning, since love and hatred are not to be known by outward prosperity and adversity, Ecclesiastes 9:1. Bar Tzemach interprets "laughing" as at his own goodness, and "rejoicing" as at the evil of the wicked.

Till--literally, "to the point that"; God's blessing on thee, when repentant, will go on increasing to the point that, or until, &c.

'Till, &c. - And what I have said in general of good men, shall be made good to thee, if thou art such: God will not forsake thee, nor desist from doing thee good, 'till he give thee abundant matter of rejoicing.