Behold, all ye yourselves have seen [it]
As they were men of observation, at least made great pretensions to it, as well as of age and experience, they must have seen and observed somewhat at least of the above things; they must have seen the wicked, as David afterwards did, spreading himself like a green bay tree, and the hypocrites in easy and flourishing circumstances, and good men labouring under great afflictions and pressures, and Job himself was now an instance of that before their eyes:
why then are ye thus altogether vain?
or "become vain in vanity" F11; so exceeding vain, so excessively trifling, as to speak and act against the dictates of their own conscience, against their own sense, and what they saw with their own eyes, and advance notions so contrary thereunto; as to affirm that evil men are always punished of God in this life, and good men are succeeded and prospered by him; and so from Job's afflictions drew so vain and empty a conclusion, that he must be a wicked man and an hypocrite.
F11 (wlbht lbh) "vanitate vanescitis", Pagninus, Junius & Tremellius, Michaelis, Schultens; "[vel] evanescitis", Montanus, Bolducius, Beza, Mercerus, Drusius, Piscator, Cocceius.