Envy refers to the desire that a person feels for the destruction or removal of a blessing that another person has – a destruction which the bearer of this feeling would himself carry out if he had the power to. This is quite different to wanting such blessings for oneself while not wishing for them to be removed from others, for that is, indeed, a positive and commendable desire that leads to competition. Competition is not considered blameworthy in general, rather it is considered to be praiseworthy if it is in pursuit of righteousness; Allah Says (what means): "Indeed, the righteous will be in pleasure. On adorned couches, observing…You will recognise in their faces the radiance of pleasure. They will be given to drink [pure] wine [which was] sealed. The last of it is musk. So for this let the competitors compete.” [Quran 83:22-26]

Allah mentions in the Quran the envy of the disbelievers, the hypocrites and people in general. Speaking about the disbelievers, Allah Says (what means): “Many of the People of the Scripture wish they could turn you back to disbelief after you have believed, out of envy from themselves [even] after the truth has become clear to them…” [Quran 2:109]

Allah also Says (what means): “Or do they envy people for what Allah has given them of His bounty?” [Quran 4:54]

Envy is an evil disease of the heart that leads to foul conduct and bad behaviour. It leads to animosity, thinking evil of the intentions of others, backbiting, tale-bearing, lying, and the abandonment of other Muslims. It may lead its possessor to inflict physical harm on the person whom he envies and can even lead to murder. It is considered to be among the most dangerous and destructive of internal diseases and is the most destructive to a person's religion and worldly life.

The Messenger of Allah (may Allah exalt his mention) said: "Do not envy one another; do not hate one another; do not turn your back on one another (in discontent); (but) be slaves of Allah as brothers." [Al-Bukhari & Muslim]

Allah orders the believers to seek refuge from the evil of the envious person and envy in general when He says (what means): "And from the evil of the envier when he envies." [Quran 113:5]

The Messenger of Allah also said: “Indeed envy eats up good deeds just as fire consumes firewood.” [Ahmad]

There are many stories in the Quran that highlight the dangers and evils of envy. When we read the story of Prophet Yoosuf (Joseph), may Allah exalt his mention, and his brothers, we realise the danger of envy, how it blinds, how it snatches mercy away from the heart, and how it drives its possessor to inflict terrible physical pain on the envied person. Allah Says (what means):  "When they [i.e., the brothers of Yoosuf] said: 'Yoosuf and his brother are more beloved to our father than we, while we are a clan. Indeed, our father is in clear error. Kill Yoosuf or cast him out to [another] land; the countenance [i.e., attention] of your father will [then] be accessible to you, and you will be, after that, righteous people.'" [Quran 12:8-9]

Another story that shows the danger of envy is the story of Haabeel and Qaabeel: The Quran tells us about the first son of Aadam, may Allah exalt his mention, who murdered his brother out of envy, which constituted the first crime ever in which blood was spilt. He envied him because Allah accepted his brother's sacrifice but not his; Allah says what means: "And recite to them the story of Aadam's two sons, in truth, when they both offered a sacrifice [to Allah], and it was accepted from one of them but was not accepted from the other. Said [the latter]: 'I will surely kill you.' Said [the former]: 'Indeed, Allah only accepts from the righteous [who fear him]. If you should raise your hand against me to kill me - I shall not raise my hand against you to kill you. Indeed, I fear Allah, Lord of the worlds.'… And his soul permitted to him the murder of his brother, so he killed him and became among the losers." [Quran: 5:27-28 & 30]

The blameworthy type of envy is an unrestricted dislike of the blessings bestowed upon the envied. Therefore, when one despises something, he is hurt and grieved by its very existence, and this becomes a sickness in his heart, to the extent that he derives pleasure from the removal of the blessings from the envied - even if this does not result in any benefit to him except having the pain that was in his soul removed.

This pain is not removed except as a result of the envier continuously monitoring the envied so that he would find relief when the blessing is removed, but it can become more severe, as is the case of the one who is suffering from a physical sickness, in that the blessing, or one similar to it, may return to the envied.
                               

The Prophet said: "I swear by the One in whose Hands is my soul! none of you will believe until he loves for his brother what he loves for himself." [Al-Bukhari & Muslim]

He also said: "There is to be no envy except in two cases: (towards) a person to whom Allah has granted wisdom, and who rules by this and teaches it to the people, and (towards) a person to whom Allah has granted wealth and property along with the power to spend it in the cause of the Truth." [Al-Bukhari & Muslim]

Ibn `Umar, may Allah be pleased with him, added to this from his own narration: "(And) a person to whom Allah has given the Quran and who recites it night and day, and a person to whom Allah has granted wealth and property from which he gives in charity by night and day."

Envy may occur as a result of enmity, pride, self-admiration, love of leadership or impurity of the soul. Of these, enmity is the most serious cause, as it leads to malevolence and this, in turn, causes man to thirst for revenge and drives him to gloat over any calamity that may afflict his enemy.

Imaam Al-Ghazzaali, may Allah have mercy on him, said in his book Al-Ihyaa': "Be aware that envy is one of the deadliest diseases of the hearts, and there is no medicine for the diseases of the heart except through knowledge and deeds. The knowledge that will treat the disease of envy is to know, without any doubt, that envy is lethal for a person's worldly life as well as his religion, and that there is no danger from it to the envied person regarding his life or his religion; on the contrary, the envied person will actually benefit from it. The fact is that envy is actually dangerous for the envier's religion because it is through this envy that he hated Allah's predestination and the blessings that He divided among his slaves; he also hated His justice that He established in His world due to His Wisdom; therefore, the envier contested that and objected to it. This is contrary to belief in the Oneness of Allah. Additionally, the envier would share with Satan and the rest of the disbelievers a love for crises to befall the believers and for blessings to leave them. These are evils in the heart that devour good deeds and erase them like the night erases the day. The person who suffers from envy in his life is tortured by it, and will always be in sorrow every time he sees the blessings of Allah upon the envied person."