For they shall eat, and not have enough: they shall commit whoredom, and shall not increase. This part of the verso states the punishment to be inflicted and the reward to be received; it is thus an expansion of the closing clause of the preceding verse, with an obvious allusion to the sin specified in the eighth verse.
To eat and not be satisfied may occur in time of famine, or be the effect of disease or the consequence of insatiable craving. "Since," says Kimchi, "they eat in an unlawful manner, their food shall not be to them a blessing."
This was one of the punishments threatened for violation of the Law, as we read in Le 26:26, "When I have broken the staff of your bread, ten women shall bake your bread in one oven, and they shall deliver you your bread again by weight: and ye shall eat, and not be satisfied."
Further, the multiplication of wives or concubines would not increase their posterity; Solomon long previously had been a notable exemplification of this. "So in their cohabitation with their women, since it is in a whorish manner, they shall not increase, for they shall not have children by them; or, if they have, they shall die from the birth."
The Hiph. hiznu has rather the intensive sense of Qal than that of causing or encouraging whoredom. Because they have left off to take heed to the Lord.