Exodus 21:26-27

And if a man smite the eye of his servant, or the eye of his maid, that it perish; he shall let him go free for his eye's sake.

If a man smite the eye of his servant ... he shall let him go free ... It may be inferred from the general equity of these laws that this provision was not confined, as some think, to Israelite servants only, but was intended for the benefit of foreign slaves also; otherwise its beneficial influence on the conduct of irritable and tyrannical masters would be greatly diminished. Their manumission was a just compensation to servants for the injury sustained; and although an eye and a tooth are specified, yet, as the one is the principal organ, and the other is a small part of the body, all other members must be considered as included in the wide range of the act.