“bronze chains.” The Hebrew is idiomatic: “double bronze.” The idea may be that each arm or leg was cuffed.

“he had to grind grain in the prison.” This was not the huge mill turned by oxen, as many works of art show; his strength was gone. This was the small hand mill that women used to grind the grain for the household. The Philistines humiliated Samson by making him do women’s work.