For they sleep not, except they have done mischief,.... Or they cannot sleep, as Jarchi and Gersom interpret it. Oftentimes they cannot sleep on their beds for devising mischief, their thoughts are so intensely set on contriving wicked schemes; and when they have so done, they cannot sleep until they have executed them; they are continually restless and uneasy day and night, like the troubled sea, constantly casting up mire and dirt. Who would keep such company as these? and their sleep is taken away, unless they cause some to fall; into the snares and traps they lay for them, or into sin and calamity by it; the former of which they endeavour by all means to draw men into, and the latter is the unavoidable consequence of it. They imitate their father the devil, both delight in sin, and in the ruin of their fellow creatures; it is a sport to thereto do mischief, and they have no pleasure without it; see Pro 11:23. What company are such!