The rules on service for the land of Israel were written before the conquest of Canaan before they took place in Israel (Deuteronomy 11:10-12 ). The cultural day to day life in Egypt and in Canaan and around the world of then serves as the background for God to formulate the Law (Leviticus 18:1-8).
When you read about laws that describe the abuse of the servants in the Pentateuch, such as abuses which result in the loss of an eye or the loss of a tooth, they were not already happening in Israel but in Egypt, in Canaan, and in the world. Moses did not get to set foot in Canaan because of what we can deem a minor disobedience, but which was nevertheless HUGE in the eyes of God: Moses did not speak to the rock, as instructed, but having been upset by the unbelief of the Israelites, he stroke the rock. What we see as dismissive, unimportant, in the Holy Scriptures is in reality very important in the eyes of God if it stands against any of the words of Jesus.
Again, when Moses wrote his book to teach the Israelites, no Israelites were already had servants whom they were beating up to break their jaws or their eyes, et cetera, which necessitated the freedom of the abused (Exodus 21:26-27). No slave traders existed yet in Israel which was yet to be.
ISRAEL DID NOT EXIST YET WHEN THE PENTATEUCH WAS WRITTEN. THE ABUSES WHICH JESUS LEGISLATED AGAINST DID NOT TAKE PLACE YET IN ISRAEL OR PERPETRATED YET BY THE ISRAELITES. THEY WERE ALREADY HAPPENING IN THE WORLD.
We know the history of the Israelites and their experience regarding their compliance with the Pentateuch.
What all men in all generations must do to be saved had been sealed in the desert with no possibility to add to the book of Moses (Deuteronomy 4:2, 5:32), and Jesus says so in Matthew 5:17-18.
If the behavior or the religious practice in Christian Judaism is not found in Moses or uttered by Jesus in parables (Matthew 13:34-35), it is of Satan.
Deuteronomy 11:10-12 ASV
(10) For the land, whither thou goest in to possess it, is not as the land of Egypt, from whence ye came out, where thou sowedst thy seed, and wateredst it with thy foot, as a garden of herbs;
(11) but the land, whither ye go over to possess it, is a land of hills and valleys, and drinketh water of the rain of heaven,
(12) a land which Jehovah thy God careth for: the eyes of Jehovah thy God are always upon it, from the beginning of the year even unto the end of the year.
Deuteronomy 12:29-32 ASV
(29) When Jehovah thy God shall cut off the nations from before thee, whither thou goest in to dispossess them, and thou dispossessest them, and dwellest in their land;
(30) take heed to thyself that thou be not ensnared to follow them, after that they are destroyed from before thee; and that thou inquire not after their gods, saying, How do these nations serve their gods? even so will I do likewise.
(31) Thou shalt not do so unto Jehovah thy God: for every abomination to Jehovah, which he hateth, have they done unto their gods; for even their sons and their daughters do they burn in the fire to their gods.
(32) What thing soever I command you, that shall ye observe to do: thou shalt not add thereto, nor diminish from it.
Leviticus 18:1-8 ASV
(1) And Jehovah spake unto Moses, saying,
(2) Speak unto the children of Israel, and say unto them, I am Jehovah your God.
(3) After the doings of the land of Egypt, wherein ye dwelt, shall ye not do: and after the doings of the land of Canaan, whither I bring you, shall ye not do; neither shall ye walk in their statutes.
(4) Mine ordinances shall ye do, and my statutes shall ye keep, to walk therein: I am Jehovah your God.
(5) Ye shall therefore keep my statutes, and mine ordinances; which if a man do, he shall live in them: I am Jehovah.
(6) None of you shall approach to any that are near of kin to him, to uncover their nakedness: I am Jehovah.
(7) The nakedness of thy father, even the nakedness of thy mother, shalt thou not uncover: she is thy mother; thou shalt not uncover her nakedness.
(8) The nakedness of thy father's wife shalt thou not uncover: it is thy father's nakedness.
Leviticus 18:22-28 ASV
(22) Thou shalt not lie with mankind, as with womankind: it is abomination.
(23) And thou shalt not lie with any beast to defile thyself therewith; neither shall any woman stand before a beast, to lie down thereto: it is confusion.
(24) Defile not ye yourselves in any of these things: for in all these the nations are defiled which I cast out from before you;
(25) and the land is defiled: therefore I do visit the iniquity thereof upon it, and the land vomiteth out her inhabitants.
(26) Ye therefore shall keep my statutes and mine ordinances, and shall not do any of these abominations; neither the home-born, nor the stranger that sojourneth among you;
(27) (for all these abominations have the men of the land done, that were before you, and the land is defiled);
(28) that the land vomit not you out also, when ye defile it, as it vomited out the nation that was before you.
Leviticus 20:23 ASV
(23) And ye shall not walk in the customs of the nation, which I cast out before you: for they did all these things, and therefore I abhorred them.
Exodus 21:26-27 ASV
(26) And if a man smite the eye of his servant, or the eye of his maid, and destroy it; he shall let him go free for his eye's sake.
(27) And if he smite out his man-servant's tooth, or his maid-servant's tooth, he shall let him go free for his tooth's sake.
Deuteronomy 4:12-14 ASV
(12) And Jehovah spake unto you out of the midst of the fire: ye heard the voice of words, but ye saw no form; only ye heard a voice.
(13) And he declared unto you his covenant, which he commanded you to perform, even the ten commandments; and he wrote them upon two tables of stone.
(14) And Jehovah commanded me at that time to teach you statutes and ordinances, that ye might do them in the land whither ye go over to possess it.
Jeremiah 10:1-6 ASV
(1) Hear ye the word which Jehovah speaketh unto you, O house of Israel:
(2) thus saith Jehovah, Learn not the way of the nations, and be not dismayed at the signs of heaven; for the nations are dismayed at them.
(3) For the customs of the peoples are vanity; for one cutteth a tree out of the forest, the work of the hands of the workman with the axe.
(4) They deck it with silver and with gold; they fasten it with nails and with hammers, that it move not.
(5) They are like a palm-tree, of turned work, and speak not: they must needs be borne, because they cannot go. Be not afraid of them; for they cannot do evil, neither is it in them to do good.
(6) There is none like unto thee, O Jehovah; thou art great, and thy name is great in might.