“Young men labor at millstones.” Many translators do not understand the huge cultural disgrace it was for a young man, especially of higher rank, to have to grind grain with a hand mill, which was always the work of women or slaves. The Philistines did the same thing to Samson (Judg. 16:21). This was not difficult physical labor, this was to disgrace them and break their spirit.
[For more on the hand mills, see commentary on Deut. 24:6.]
“boys stumble under loads of wood.” It is hard for us today to imagine the immense amount of wood that was burned in the ancient world. Everyone cooked with it, warmed themselves with it, and used a tremendous amount of it to burn all their various sacrifices. If a person had slaves, one of their jobs was almost always to carry wood (cp. Josh. 9:21, 23, 27).