שֶׁ֚בֶר תַּ֣חַת שֶׁ֔בֶר עַ֚יִן תַּ֣חַת עַ֔יִן שֵׁ֖ן תַּ֣חַת שֵׁ֑ן כַּאֲשֶׁ֨ר יִתֵּ֥ן מוּם֙ בָּֽאָדָ֔ם כֵּ֖ן יִנָּ֥תֶן בּֽוֹ׃
брешь за брешь, око за око, зуб за зуб; как он покалечил человека, так и будет ему дано.
Rashi
כן ינתן בו [AND IF A MAN CAUSES A BLEMISH IN HIS COMPANION…] SO SHALL IT BE DONE TO HIM — Our Rabbis explained that this does not mean the actual infliction of a blemish but that it means monetary compensation — that we estimate his (the injured man’s) value as a slave and the offender has to pay the difference between his value as an unmaimed man and that which he represents after the infliction of the injury. It is for this reason that the term נתן “to give” is written here referring to something that is given (passed) from hand to hand viz., money (Ketubot 32b; Bava Kamma 84a).
Ibn Ezra
In addition, Sa‘adya Gaon has brought numerous other proofs, from simple common sense, that Scripture could not mean a fracture for a fracture literally. For example, since the original wound was not precisely calculated, how could one duplicate it exactly? If not, and if the wound is in a sensitive area, one might kill the guilty party inadvertently! If someone removed one-third, say, of another person’s eyelid, how could one possibly give the guilty party precisely that wound? Accordingly, the words of the tradition [Bava Qama 83b] must be correct. The true explanation in all these cases is that the guilty party deserves to lose an eye, but instead, he pays its monetary equivalent. If people should ask, “what if the guilty party is poor?” we answer that the law deals with the cases that are likely to occur. Besides, we can throw the question back at the questioners: What if the guilty party is blind? At least a poor person can conceivably become rich! [see also comment on Exodus 21:24] so it shall be given upon him [literally: with him] [to “give upon” someone in Hebrew means to fine him — Translator] Often, the letter bet [“with”] takes the place of the preposition “upon”. Compare, “upon [literally: with] which I rode” [Nehemiah 2:12]. Many other examples exist. or so it shall be given in him — i.e., so shall it be done to him — if he does not compensate his victim.
Chizkuni
כן ינתן בו, “so shall be done to him;” Rashi on this verse comments that the text is not to be understood literally, but what is meant is that financial compensation must be paid to the victim. This is perfectly logical, as in many instances it would be impossible to carry out the literal meaning of the text, and it would even be totally unfair, for instance, for a one eyed person to have to lose one eye if he had gouged out the eye of a person who had two good eyes with which to see. Our sages’ interpretation of this verse is therefore clearly the correct one. (Ibn Ezra) If the aggrieved party should take issue with this by arguing that he is not to blame that the person who had gouged out one of his eyes had only had a single eye, and that he insists on the literal application of this verse, he is told that the Torah was written in order to address normal situations, not exceptional situations, for if it had intended to provide in its text for every imaginable contingency, the Torah would be far too long. Moreover, even assuming after the exceptions the Torah sometimes made for a person’s financial circumstances, this would not necessarily be fair, as who knows whether a person who is poor today may not become rich next week or vice versa? The overriding consideration for compensation if a life had been taken deliberately is spelled out by the Torah when it wrote that financial compensation for taking a life is absolutely inadmissible, as who can determine the value of a person’s life in terms of money? (Numbers 35,31) Individual limbs, however, are subject to the judges’ evaluation