Charles Ellicott Commentary Judges 16:21

"And the Philistines laid hold on him, and put out his eyes; and they brought him down to Gaza, and bound him with fetters of brass; and he did grind in the prison-house." — Judges 16:21 (ASV)

Put out his eyes. —The marginal note, “bored out,” is more correct. The Arabic version has the curious gloss that they burnt out his eyes with the red-hot stylus with which stibium is applied to the eyes. To blind a man was the most effectual humiliation (2 Kings 25:7). The story of Evenius, a priest of the sun-god, who is blinded by the people of Apollonia, who thereby incur the anger of the gods, seems to move in a similar circle of ideas to this.

Fetters of brass. —Literally, two brasses — i.e., pairs of brazen fetters (nechushtarim).

He did grind in the prison house. —This was the degrading work of slaves and females (Exodus 11:5; Isaiah 47:2). Grotius in a curious note says that slaves thus employed were blinded by the Scythians to save them from giddiness . The end of Samson was mournful; “his whole powerful life was only like a light, blazing up brightly at moments, and shining afar, but often dimmed, and utterly extinguished before its time” (Ewald).