Either justice and legitimacy or anarchy and death!
"O ye who believe! Eat not up your property among yourselves in vanities: But let there be amongst you Traffic and trade by mutual good-will: Nor kill (or destroy) yourselves: for verily Allah hath been to you Most Merciful! If any do that in rancor and injustice,- soon shall We cast them into the Fire." (an-Nisa: 29, 30)
We explained the verses above as follows in the tafsir called Kur'an Yolu:
In the previous verses, legitimate ways like inheritance, donation and mahr that were used in the transfer of wealth and material interests were mentioned. In the verses above, trade is mentioned in its widest sense, that is, in the sense of “legal transaction that is based on mutual consent and that is about material values"; the verses forbid taking people’s things and benefitting from them through the ways that are contrary to those mentioned above and hence that are called wrong ways.
Theft, seizure, bribery, corruption, usury, pawn-broking, price gouging, deceiving are the most important and common forms of those wrong ways. Trade is generally done by adding some profit to the goods that are bought. The price is determined when it is bought. Since it is not transferred with the same price while selling, this profit – which consists of the extra money, resembles “wrong ways of earning” and reminds them.
Probably due to this reason, when unjust profit is forbidden, trade is rendered free as an exception. Profit, which consists of the price of difference between the purchasing price and the selling price, is legitimate. For, the merchant who buys and sells goods does something useful for the public and risks his capital, along with working. After prohibiting black marketing, Hz. Umar said, “... however, anybody who brings goods to the market by taking pains in summer or winter is Umar’s guest; he can sell them as he wishes." Thus, he indicated that reason. (al-Muwatta', “Buyu' ", 56) Those elements and qualities do not exist in wrong ways; the strong oppress the weak and benefit from their weaknesses and needs; they take their goods without the real consent of the weak.
The phrase “do not kill yourselves" includes important and subtle points aiming to maintain both life and public order. It is especially remarkable that the phrase “do not kill yourselves" is used after goods are prohibited to be eaten up and used through unjust ways. Injustice and legal and social unfairness bring about or increase anarchy; once the public order is broken, and law and order disappear, safety of life falls into danger. Not only those who are wronged but also those who eat up others’ goods unjustly and those who kill others unjustly are affected by this insecurity; they can be killed; the lives and goods of their relatives can be harmed. Although the real purpose of the verse is to forbid killing others, the phrase “do not kill yourselves" is used meaning others; it is a great emphasis in terms of protecting right to live. For, there is no difference between a person’s own life and the life of another person; all lives deserve to be protected equally; they have the right to be protected. A person who kills another person needs to think that he kills himself; he needs to have this consciousness.
The verse contains two of the “five necessary/important values and purposes (maqasid ash-shari’ah) that need to be protected", which are the purpose of all muamalat decrees of Islam: Protection of life and protection of wealth. The previous verses contain the principle of protecting the generation by encouraging marriage and prohibiting fornication; verse 43 of the chapter contains the principle of protecting the mind by prohibiting becoming drunk; and the orders of obedience to Allah and worshipping Him, obedience to His Messenger and following him, belief in the religion conveyed by all prophets and following it, which are often repeated in various places, contain the purpose of protecting the religion.