According to the faqihs, usurpation refers to usurping other's possessions by force without having the right to take them.

　　Usurpation is prohibited according to juristic consensus, for Allah, The Exalted, Says (what means): {And do not consume one another's wealth unjustly...} [Quran 2: 188]

　　Usurpation is considered one of the grievous ways of eating up money unjustly, for the Prophet () said: “Verily, your blood, property and honor are sacred to one another (as Muslims).” (Muslim)

　　He () also said: “The property of a Muslim is not lawful (to be taken) except by his consent.” (Abu Ya' la in his Musnad')

　　The usurped wealth could be real estate or a movable property; the Prophet () said: “If anyone extorts a span of land unjustly, his neck will be encircled with it down seven earths (on the Day of Resurrection).” (Al-Bukhari and Muslim)

　　A usurper has to repent to Allah, The Almighty and Ever-Majestic, and return whatever he has extorted to its rightful owners, asking them for forgiveness. The Prophet () said: “Whoever wrongs anyone in a matter that concerns his honor or any other matter should ask his forgiveness as soon as possible, before a time comes when there is neither dinar nor dirham (i.e. before the Day of Resurrection when wealth cannot compensate for one's wrongdoing); if the usurper has good deeds, they will be taken from him according to his usurpation, and if he has no good deeds, the sins of the oppressed person will be loaded on him.” (Al-Bukhari)

　　If the usurped property is available, he should return it in the same condition he has taken it, but if it is damaged, he should return its equivalent.

　　Imam A1-Muwaffaq said: “Scholars unanimously agree that it is obligatory to return the usurped property if it is still in the same condition and unchanged.” (Al-Mughni and Ash-Sharh AI-Kabir)

　　Furthermore, the usurper has to pay back the usurped property along with the profit he has made through it, be it connected with the property or separated. This is because the profit is the outcome of what has been taken unjustly, so it belongs to its rightful owner just like the original usurped property.

　　If the usurper has built on the usurped land or has planted vegetation therein, he has to remove the building or the crop in the case the rightful owner demands so. The Prophet () said: “The unjust root (planted in someone's land without his permission) has no right.” [At-Tirmithi and other compilers of Hadeeth; At-Tirmithi regarded it as a hasan (good) Hadeeth]

　　If so doing will negatively affect the land, the usurper has to compensate for the damage. He has also to remove the remains of the crop or the structure so that he may deliver the land in good condition to its rightful owner.

　　The usurper has also to pay a compensation for using the land from the date of its usurpation until its delivery, as he has unrightfully prevented its owner from using it during that period. Moreover, if the usurper withholds the usurped property until its value and price are reduced, he has to pay it back according to its original price according to the sound opinion in this regard.

　　On the other hand, if the usurped object is mixed with something else that can be distinguished from it - like wheat and barley - the usurper has to separate what he has usurped and return it. If he has mixed it with something that cannot be distinguished, such as mixing wheat with wheat, he has to pay back the usurped object in measure or weight. Yet, if he has mixed the usurped object with something of inferior or superior quality, or with something different but indistinguishable, the mixture is to be sold and each one of them is to be given his share of the price. In this case, if the value of usurped property is less in the mixture than its value when unmixed, the usurper has to compensate the owner for the decrease in its price.

　　Among the juristic opinions in this connection is that whoever takes the usurped property from the usurper is financially liable for it in case it is damaged in his possession.

　　There are ten examples of people who may take a usurped property from the usurper:

　　1. One who may buy the usurped object from the usurper or the like.

　　2. One who may rent the usurped object from the usurper.

　　3. One who may be granted the usurped object by the usurper gratis.

　　4. One who may take possession of the usurped object on behalf of the usurper such as a trustee or a deputy.

　　5. One who may borrow the usurped object from the usurper.

　　6. One who may usurp the usurped object from the first usurper.

　　7. One who may have the usurped object at his disposal, such as a speculator on behalf of the usurper.

　　8. One who may marry an appropriated bondmaid from her usurper.

　　9. One whom the usurper may grant, not sell him, the usurped object as a compensation for something.

　　10. One who may damage the usurped object while having it on behalf of the usurper.

　　In all these cases, if the second party is aware that the object is originally usurped, he becomes financially liable for it for obtaining something without the permission of its rightful owner. However, if he is unaware of that, the original usurper shoulders the liability.

　　If the usurped property is something that is usually rented, the usurper is to pay compensation estimated according to the period of his possession of the usurped property. This is because utilities represent assets, so they have to be paid for just like real estate.

　　All the dealings of a usurper on the usurped object are invalid, as they are carried out without the permission of the rightful owner.

　　If the usurper does not know the owner of the usurped object and thus is unable to return it to him, he should deliver it to the ruler (or the one in authority) to put it in its right place or give it in charity on behalf of its owner. In so doing, the real owner of the usurped object will get the reward of charity, and the usurper becomes free from the guilt.

　　The usurpation of a property is not limited to taking it by force; it rather includes seizing it through unjust disputes and false oaths. Allah, The Exalted, Says (what means): {And do not consume one another's wealth unjustly or send it [in bribery] to the rulers in order that [they might aid] you [to] consume a portion of the wealth of the people in sin, while you know [it is unlawful].} [Quran 2: 188]

　　Allah Almighty also Says (what means): {Indeed, those who exchange the covenant of Allah and their [own] oaths for a small price will have no share in the Hereafter, and Allah will not speak to them or look at them on the Day of Resurrection, nor will He purify them; and they will have a painful punishment?} [Quran 3: 77]

　　In fact, the Divine command is so strong and binding, and the punishment of violating it is so severe.

　　Moreover, the Prophet () said: “If anyone extorts a span of land unjustly, his neck will be encircled with it down seven earths (on the Day of Resurrection).” (Abu Daawood, At-Tirmithi, Al-Bukhari)

　　He () also said: “If I gave some one's right to another (mistakenly because of the latter's tricky presentation of the case), he (the latter) should never take it, for I would be really giving him a piece of fire.” (Al-Bukhari and Muslim)

　　Source: Aljumuah