They conceive mischief
That is, such wicked persons as before described; they meditate sin in their minds, and contrive how to commit it, and form schemes within themselves to do mischief to others:
and bring forth vanity;
or sin; for lust when it is conceived bringeth forth sin, and that is vanity, an empty thing, and neither yields profit nor pleasure in the issue, but that which is useless and unserviceable, yea, harmful and ruinous; for sin, when it is finished, bringeth forth death, even death eternal, ( James 1:14 James 1:15 ) ;
and their belly prepareth deceit;
their inward part frames and devises that which is designed to deceive others, and in the end proves deceitful to themselves: the allusion is to a pregnant woman, or rather to one who seems to be so, and whose conception proves abortive, and so deceives and disappoints herself and others; see ( Psalms 7:14 ) .