For they sleep not, except they have done mischief; and their sleep is taken away, unless they cause [some] to fall.
Ver. 16. For they sleep not.] So much are they set upon it. Or as empty stomachs can hardly sleep, so neither can graceless persons rest till gorged and glutted with the sweetmeats of sin, with the murdering morsels of mischief. The devil, their taskmaster, will not allow them time to sleep; which is very hard bondage. "They have eyes full of adultery, and that cannot cease to sin." 2Pe 2:14
Unless they cause some to fall.] Protagoras, as Plato relates, boasted of this, that whereas he had lived threescore years, forty of them he had spent in corrupting of young men that conversed with him.