A seriously misunderstood passage is Exodus 21:20-21.
If a man beats his male or female slave with a rod and the slave dies as a direct result, he must be punished, but he is not to be punished if the slave gets up after a day or two, since the slave is his property.
The passage is often cited as proof that the Bible supported chattel slavery. This is not true, but this idea has been encouraged by bad translation.
The first problem is with the word "slave". This is a serious mistranslation the Hebrew. The word translated as male slave is "Ebed". The word translated female slave is "Amah". The NIV translates these words in different ways in different parts of Exodus 21; as slave in verses 20 and 32, and as servant in verses 26 and 27. There is no reason for the difference, and servant is a better translation.
They boy Samuel called himself the Ebed of God. Gehazzi was the Ebed of Elijah. The suffering servant of Isaiah was an "ebed". An Ebed might be bonded to his master for a time, because he has fallen into debt, but he would not be a slave in the modern sense of the word. The NIV is quite mischievous in the way it sometimes uses the word slave for this word. The NKJV is more consistent and always uses the word servant. The Israelites were not allowed to enslave their countrymen (Lev 25:39).
This passage refers to servants, not slaves.
The problem with Exodus 21:20-21 is the last clause: "the slave is his property". A literal rendering of the Hebrew text is,
He his silver
It is not clear who the "he" refers to. It could be the master and it could be the servant. The same applies to the possessive pronoun "his".
The Hebrew word used for silver is "keseph". It is sometime used for coins, but can also refer to silver metal. The same word is used in later in the same chapter to describe the penalty for a man who leaves a dangerous pit open.
And if a man opens a pit, or if a man digs a pit and does not cover it, and an ox or a donkey falls in it, the owner of the pit shall make it good; he shall give money to their owner, but the dead animal shall be his (Ex 21:33-34).
The word translated money is "keseph". In this example, it refers to the money paid to make restitution for harm done to another person. It follows that in Exodus 21:20- 21, the word "keseph" also refers to restitution and not to chattel slavery. The passage is just a further amplification of the law of financial restitution that is described in Exodus 22.
The man does not need any other punishment, because he must make restitution for the damage he has done. A better translation would be,
He must receive silver from him.
Equal under the Law
The references to servants in Exodus 21 are really important, because they give servants the same protection as other citizens. This is quite unique, as in most other jurisdictions, servants were not protected by the law. The point of Exodus 21:20- 21 is that a master who kills his servant must receive the same punishment as he would if he had killed any other person, as specified in Exodus 21:12-13. Servants were not excluded from the law.
If the servant gets up after a couple of days, the master does not receive the penalty for murder, because the servant will receive financial restitution to compensate him for his injuries. The master must pay silver to the servant as restitution, so he should not receive any physical punishment.
A clearer expression of Exodus 21:20-21 would be the following.
If a man beats his male or female servant with a rod and the servant dies as a direct result, he should receive the penalty for murder, but he if the slave gets up after a day or two, he must not be punished for murder, but the slave should receive financial compensation from him.
Subsequent verses give even greater protection to bonded servants.
If a man hits a manservant or maidservant in the eye and destroys it, he must let the servant go free to compensate for the eye. And if he knocks out the tooth of a manservant or maidservant, he must let the servant go free to compensate for the tooth (Ex 21:26-27).
The previous verses had explained that a person who assaults another, must make full financial compensation to the victim. These verses clarify any confusion about whether these requirements apply to bonded servants.
God's law actually imposes an even higher standard on people with bonded servants. If a citizen has a tooth knocked out, they must receive full restitution equivalent to the value of the tooth. The value of the tooth would not be that great. If a man assaults his servant and knocks out a tooth, he must let the bonded servant go free by writing off the total debt that was owed.
In most cases, the debt being cancelled would be worth far more than the tooth. This means that the punishment for a assaulting a bonded servant was greater than for assaulting another citizen. Biblical law recognises the fact that bonded servants are in a vulnerable position, so it provides them with greater protection. If man is violent and inflicts physical harm on a bonded a servant, he must release him from his debt. This could be a very severe penalty.
Exodus 21 does not justify slavery, it is actually the opposite. It explains that the laws against assault apply equally to servants, as to citizens. The only exception is that bonded servants receive even greater protection, because they are in a defenceless situation. Exodus provides protection for the weak, it does not take away their rights.
Exodus 21 is a passage specifying punishments for crimes. Therefore it is the last place that you would expect a theology of slavery. Building a justification for chattel slavery on an obtuse translation of a verse that is difficult to translate is quite unwise.