You have heard that it was said: "An eye for an eye, and a tooth for a tooth."
In this saying, Jesus refers to the Old Testament law, “An eye for an eye, a tooth for a tooth” (Exodus 21:24, Leviticus 24:20, Deuteronomy 19:21), which was intended to limit revenge. At that time, the principle “an eye for an eye” established that the measure of punishment had to be equal to the harm, not allowing revenge to go beyond the extent of the injury. This was then a means for keeping justice within proper bounds and for preventing harsh or disproportionate penalties. It was regarded as a principle of justice and responsibility that restrained vengeance, because it did not allow the punishment to be greater than the damage that had been done.