When Y'shua says, "you have heard it said" he refers to oral tradition; when he says "it is written" he refers to Scripture. The matter of an eye for an eye and tooth for a tooth, according to Torah, refers to fair restitution; not literally taking out an eye or tooth. The amount to be restored must be commensurate to the loss; the loss of an eye must be rewarded the value of an eye. See Exodus 21:24; Leviticus 24:20; Deuteronomy 19:21. Torahless ultra-religious judges or pagan cultures opted for barbaric punishment as crime for crime, however this is not a Torah principle.
Do not react with evil towards evil, rather let patience and temperance prevail when accosted by evil doers. Torah instructs the strong to protect the weak, Deut 22:27. Ya'akov teaches to "stand firm" against Satan, James 4:7. Paul teaches to stand against the strategies of the Accuser in Ephesians 6:11; neither does he mince words in Acts 13:10.
Isaiah 14:15 states that haSatan will be brought down to hell and a slaughter is prepared for his children (verse 21). Rev 20:10 promises a date for Satan in the lake of fire, in the meantime we are to recognize that our battles are not against flesh and blood, and to act accordingly.
We must remember that Y'shua taught his followers to make sacrifices for the Kingdom and to "take up their cross" and follow him. Many Christians take these ideas literally, knowing what he did on the stake; and, at certain times of the year, they parade large wooden crosses through the streets of their cities. While Y'shua predicted hardships for his followers, he also told them to rejoice when it happened - but this didn't mean he wanted them to roll over and play dead. Clearly he intended his followers to live!
And while it is true that Y'shua instructed his disciples not to resist his accusers on his behalf (when he was being arrested), that does not mean he taught against self-defense. Y'shua, in fact, instructed his disciples to buy swords in Luke 22:36-38 in spite of the reference in John 18:10-12 concerning his knowledge that a contingent had come against him as part of his mission. That is why Y'shua says in John 18:33-37, "My kingdom is not of this world. If it were, my servants would fight to prevent my arrest by the religious authorities. But now my kingdom is from another place." "You are a king, then!" said Pilate. Y'shua answered, "You are right in saying I am a king. In fact, for this reason I was born, and for this I came into the world, to testify to the truth. Everyone on the side of truth listens to me."
Y'shua clearly teaches that his kingdom does not exist based on people dying even to save his life! Yet in Matthew 5:38-42 many assume that "do not resist an evil person" means to be a pacifist, when in reality, it simply means to not repay evil with evil!
As everyone knows, a person who unjustly assaults or steals from his fellow man is subject to penalty and discipline, and is required to make restitution. In ancient times it was not uncommon for some to try to "get even" with an adversary by killing them over very minor offenses, even going so far as to murder that person's family. Therefore YHWH put a limitation on vengeance (i.e. take one eye for an eye), the opposite of what has been taught in the Christian West which views "eye for an eye" as the judgments of a wrathful Elohim.
In addition, Torah rightfully interpreted and understood is the most just and fair of any legislation on this earth. Where else in the world were the rich commanded to leave the edges of their fields un-harvested so as to feed the poor? Nowhere! Where else were the rich required to make non-interest bearing loans for the poor? Where else are criminals required to make restitution for their lies and stealing so that anyone who participated in criminal activity could be rehabilitated and treated as an equal? In most countries there is no legislation to rehabilitate criminals or make restitution for what they have stolen from others, yet many people think and speak very evil things against Torah.
Y'shua always taught obedience to the law! In other words, if someone is going to sue for your tunic and cloak - the the only two pieces of clothing a Jew was required to wear - it must truly be for a very good reason. If the judge then grants the plaintiff's request, the guilty party must comply, even if it means he will be going home naked. Granted this is an extreme example, but it is exactly the kind of graphic imagery that Y'shua knew would have an impact on his listeners.
Finally, Y'shua advised his followers to do everything they could to prevent such lawsuits. If we give more than we are actually asked to, no one can hold us guilty. But it is the "flip side" to that concept that relates to the heart of what we are discussing. An investigation of Matthew 5:25-26 indicates that settling matters with your adversary is far better than a confrontation in court. Even if you are in the right it is always in your best interests to do whatever you can to resolve the matter outside of court.
Y'shua calls his followers to be beyond reproach so that false accusations against them will not have a negative impact. He knows that "they will lay hands on you and persecute you" on account of his name's sake (Luke 21:12) and he tells us: "If the world hates you, keep in mind that it hated me first." (John 15:18-25) Nevertheless, the fact remains that Y'shua always expects the best possible efforts from his followers, and this is where "turning the other cheek" really comes into play.
Keefa (Peter) was rebuked for cutting off the ear of a member of the arresting party. Y'shua felt so strongly about this being wrong that he restored the stricken man's ear. Why? Because he didn't want to escalate the situation and risk the safety of his own disciples.
Y'shua wanted the assaulter to have an opportunity to re-think his actions. Oftentimes assaults are made during momentary acts of emotion. For these reasons, Y'shua says turn your left cheek, and then see if your attacker is running on their emotions. Most people, if given a moment to think about what they are doing, would probably not resort to violence. However, even if someone did, the act would indicate the intent and be so blatant that it would virtually guarantee either arrest and/or conviction of assault. Either way, this would again serve as an opportunity for both parties to make one final attempt toward reconciliation before escalating the matter further and winding up in court.