Matthew Poole and continuators on Lamentations 5:13

13 They took the young men to grind, and the children fell under the wood .

Their base servile condition is expressed by the labour they were put to, which was either grinding in the Mill (an ordinary employment of Slaves in those Countries) or carrying Millstones, and the younger Children, in carrying great burdens of wood under which they fell, as being not able to stand under the burdens laid upon them.