These are but more metaphorical expressions, signifying the unpleasant difficult condition into which God had brought this people. They were like men that lived upon gritty bread, more fit to break their teeth than to nourish them; they were in the state of mourners, and no ordinary mourners, who were wont to throw ashes on their heads, they were all over covered with ashes.
Related Commentaries of Lamentations 3:16
Lamentations 3:16
16 He hath also broken my teeth with gravel stones, he hath coveredc me with ashes.