God intended the "eye for eye" provision to limit punishment rather than giving free reign to it. The law of retaliation (Latin lex talionis) became common in the ancient Near East. It sought to control the tendency of someone who had only suffered a minor injury to take major revenge. For example, a man might kill the person who beat up his brother (cf. Genesis 4:23). God forbade such excessive vengeance among His people and limited them so that they should only exact equal payment for offenses committed against them and no more. [source][source][source]
"This law of the talion, for a long time thought to be a more primitive kind of penalty, the reflection of a barbaric law form, has been shown by more recent comparative studies to be a later development, designed to remedy the inevitable abuses made possible by monetary payment for physical injury." [1][source]
"According to Num. xxxv31it is only from a willful murderer that it is forbidden to accept ransom [2]; this implies that in all other instances the taking of a ransom is permitted.... [source][source][source]
"This being Song of Solomon , the meaning here in our paragraph of the expression life for life [3] is that the one who hurts the woman accidentally shall be obliged to pay her husband the value of her life if she dies, and of her children if they die." [4][source]