Muslim

Hadith Commentary: Benefits and Issues: The Jews devised this stratagem for using fat (shahm): they would melt it so that it would become wadak (liquid fat) instead of shahm, because among the Arabs, before melting it is called shahm, and after melting it is called wadak. In this way, through this stratagem, they began to use it—either by selling it and consuming the proceeds, or by using it themselves. From this, it is understood that devising a stratagem to evade a legal (shar‘i) ruling is not permissible. However, it is permissible to devise a stratagem (tadbeer) for the implementation of a legal ruling or to avoid its violation. Deception and trickery are not permissible.

Therefore, it is not correct to use as evidence, for the sake of trickery, the Qur’anic verse: “Take in your hand a bundle of twigs” (), or “He placed the cup in his brother’s saddlebag” (), because these actions were done by the command and explicit text (nass) of Allah Ta‘ala; they were not adopted independently by Prophet Ayyub or Prophet Yusuf (alayhima as-salam). Similarly, when the Prophet (sallallahu alayhi wa sallam) instructed to sell inferior dates and buy good dates with the proceeds, there was nothing deceitful in this; rather, it was the command of the Lawgiver (Shari‘), and it was not done independently as the Jews did.

Turning wine into vinegar is a person’s own action, whereas the Lawgiver has prohibited selling wine. So a person, in order to sell it, altered it from its original state—just as the Jews began to sell fat by turning it into wadak. Likewise, the Jews would not catch fish on the Sabbath; they would only catch them after the Sabbath had passed. On the Sabbath, they would merely set the nets or drive the fish into pits (through holes), and this became a cause of punishment for them.

Hadith Commentary:
They resorted to trickery to make it lawful for themselves, and because of this action, a curse was invoked upon them.
It is evident from this that using tricks and excuses to alter any legal (shar‘i) ruling is an extreme crime, and to make something lawful unlawful, or to make something unlawful lawful through some trick, is a cause for curse.
But, alas, the esteemed jurists (fuqaha) have even authored independent books on legal stratagems (kitab al-hiyal).
In these, numerous methods for devising unwarranted tricks and excuses have been described—may Allah have mercy.

Hadith Commentary:
(1)
From this hadith, it is understood that such trickery and seeking of means which lead a person to a prohibited act are unlawful (haram) and forbidden. It is also understood that consuming the price of something whose essence is haram is itself haram.
At the end, Imam Bukhari rahimahullah has interpreted "qatil" as "cursed," and he has derived this meaning from the Qur'an.
In the Noble Qur'an it is stated:
﴿قُتِلَ الْخَرَّاصُونَ ﴿١٠﴾
Ibn Abbas radi Allahu anhu has interpreted this as "accursed," and "kharrasun" means "liars."
Imam Mujahid has adopted this interpretation.
(Fath al-Bari: 4/525)
(2)
It should be clear that according to this hadith, transforming the form of haram things and then selling them, and using their price, is haram.

Hadith Commentary: Benefits and Issues: Certain things are prohibited to eat according to Islamic law, therefore, buying and selling them for the purpose of eating is also prohibited. However, their other uses are permissible, so selling them for other benefits is also permissible, such as donkeys, mules, and hunting birds—their buying and selling is permissible. Similarly, it is permissible to tan and sell the hide of a dead animal.