Allah, Glorified and Exalted be He, cautions us saying,
And do not eat up your property among yourselves for vanities. (AI-Baqarah: 188)
The verse means that Muslims are commanded by Allah to avoid taking the property of each other’s through illegal means. Abdullah Ibn Abbas (may Allah be pleased with them both) said, "What is meant in the verse are the false oaths through which a person takes the property of another with no right."
The consumption of Haram is of two kinds:
The Messenger of Allah (pbuh) has condemned the consumption of the Haram in many ahadith. Here, we will quote the following ahadith to explain the gravity of this heinous sin:
The Messenger of Allah (pbuh) said,
"Some people spend Allah's wealth (i.e., the Muslims' wealth) in an unjust manner; such people will be put in the Hell on the Day of Judgment.” [Bukhari]
"... Then he mentioned (the case of) a man who, having journeyed far, is disheveled and dusty and who spreads out his hands to the sky saying, O Lord! O Lord! While his food is unlawful, his drink unlawful, his clothing unlawful, and he is nourished unlawfully, how can he be answered?” [Muslim]
Anas (may Allah be pleased with him) said to the prophet (peace and blessing be upon him) 'O Messenger of Allah! Supplicate to Allah for me to make my Dua acceptable." The Messenger (pbuh) replied,
"O Anas! To have an acceptable Dua, you should eat only the Halal (Lawful) since a person may be deprived of his Dua being answered for forty days because of eating a mouthful of Haram food.” [Al-Asfahani in al-Targhib]
"Allah has decreed your behaviour as He has decreed your provision. Surely, Allah grants the joys of this world to those whom He loves and those whom He loves not, but He does not grant religion except to those whom He loves. Therefore, those who are blessed with religion receive Allah's Love. Assuredly, no one earns Haram money but what he spends, gives as charity or leaves behind will be his fuel in Hell-fire. Verily Allah does not obliterate evil by means of evil, but He obliterates evil by means of good.” [Musnad Ahmad]
"This worldly life is joyful and attractive. Therefore, whoever earns property through lawful means and spends it in a legal manner, Allah will reward him with Paradise. On the other hand, whoever earns property through unlawful means and spends it in illegal ends, Allah will make him dwell in the abode of humiliation (Hell). Some people also spend Allah's wealth in an unjust manner according to their whims. Such people will be put in the Hell on the Day of Judgment.” [Ibn Hibban]
"Whoever pays no attention to the sources of his money, Allah will not concern about which gate he would enter Hell-Fire.”
Abu Hurairah (may Allah be pleased with him) reported a hadith that reads,
"To fill his mouth with dust is better to a person than putting Haram things in it.” [Musnad Ahmad]
Yusuf Ibn Asbat (may Allah bestow mercy on him) said, "When a young man dedicates his life to worship, Satan asks his assistants about the source of his livelihood. If it is Haram, Satan says, 'Don't bother about his worship and dedication for his consumption of the Haram is sufficient to make his work null and void.'" This means that worship will be of no avail when the worshiper insists on eating Haram. This meaning is maintained by the aforementioned Hadith that,
"... A man who, having journeyed far, is disheveled and dusty and who spreads out his hands to the sky (saying), 'OLord! O Lord!' while his food is unlawful, his drink unlawful, his clothing unlawful, and he is nourished unlawfully, how can he be answered?” [Muslim]
It is reported in the hadith that,
"Every day and night, an angel calls upon people from above Jerusalem,
'Whoever indulges in eating Haram, Allah will never accept his optional or obligatory acts of worship.'"
Abdullah ibn Al-Mubarak said, "Keeping myself clean from consuming a doubtful dirham is more charitable to me than giving 100,000 dirham in charity."
The Prophet (pbuh) said,
"When the pilgrim, who journeys to Hajj, by Haram money, says. Here I am! At your service. Our Lord, here I am! At your service. Allah will say to him, your calling is rejected and your Hajj is valueless.” [lbn Hajar Al-Haithami, Majma Al-Zawaid]
He (pbuh) also said,
"Whoever purchases a garment by ten dirham which contain a Haram dirham, Allah never accepts his prayer as long as he wears this garment.” [Ahmad]
Wuhaib Ibn AI-Ward said, "If you were to stand in Prayer equally as this column stands in the mosque, it would be of no avail until you take care about your livelihood, i.e., to verify what is lawful from what is Haram."
Ibn Abbas (may Allah be pleased with them both) said, "Allah never accepts the Prayer of a man who feed on Haram until he repents."
Similar to the one who spends unlawful money in disobedience of Allah is the one who purifies his garment by urine. Assuredly, only water can purify one's garment just only as the lawful can obliterate sins."
Umar (may Allah be pleased with him) said, "We used to abstain from nine tenths of Halal lest it may contain a Haram."
“A body that is nourished unlawfully will not enter paradise.” [Tabarani]
Zaid Ibn Arqam reported that, "Abu Bakr had a slave who used to give him some of his earnings. Abu Bakr used to eat from it. One day he brought something and Abu Bakr ate from it. The slave said to him, 'Do you know what is this?' The slave said, 'Once, in the Pre-Islamic Period of ignorance I sold somebody's future though I did not know this knowledge of foretelling but I cheated him, and when he met me, he gave me something for that service, and that is what you have eaten from. Then Abu Bakr put his hand in his mouth and vomited whatever was present in his stomach." Later on, Abu Bakr was asked, “O Abu Bakr! Have you done all this because of a Haram mouthful?" He replied, "By Allah! If I were to perish myself to get this mouthful out of me, I would have no hesitation to do so because I heard the Messenger of Allah say,
Everybody that is nourished unlawfully, Hell would be his abode.” [Bukhari]
However, the Muslim scholars state that the consumption of Haram includes various major sins such as treachery, oppression, robbery, usury, taking the orphan's property with no right, false witness, bribery, deception, gambling, sorcery, foretelling, adultery, fornication, and the practice of wailing, lamenting and showing excessive grief for the dead.
The Messenger of Allah (pbuh) said,
"On the Day of Judgment, there will come some people with righteous deeds which are as huge as the Mount of Tuhamah. These righteous deeds would be soon scattered and invalidated. Consequently, those people would be thrown into Hell-fire." The Companions (may Allah be pleased with them) wondered, "O Messenger of Allah! How would this happen!" He (pbuh) replied, "Those people used to perform Prayer, fast, gives Zakah and offer Hajj, but they used to consume Haram so Allah invalidated their righteous deeds.” [Tabarani]
It is narrated that a righteous man was seen in a vision after his death and was asked about his affair. Thereupon this man explained, "Fine! But I have been prevented from entering Paradise because of a needle which I borrowed in my life and did not give it back to its owner."
Ascribing Associates To Allah, the Most High (Shirk)
Killing A Human Being
Not Performing The Prayer
Not Paying Zakat
Breaking One's Fast During Ramadan Without An Excuse
Not Performing the Hajj when Able to
Showing Disrespect to One's Parents
Severing the Ties of One's Relatives
Accepting Usurious Gain
Wrong Consuming An Orphan's Property
Lying About The Prophet
Fleeing From The Battlefield
The Leader Who Misleads His Followers, The Tyrant And The Oppressor
Arrogance, Pride, Conceit, Vanity And Haughtiness
Bearing False Witness
Accusing A Woman Of Adultery
Misappropriating Spoils Of War, Muslim Funds Or Zakat
Highwaymen Who Menace The Road
The Engulfing Oath
Taking People's Property Through Falsehood
The Consumption of Haram
The Dishonest Judge
Women Imitating Men And Vice Versa
The Pimp and the one Who Permits His Wife to Fornicate
Marrying Solely To Return To The Previous Husband
Not Freeing Oneself Of All Traces Of Urine
Showing Off In Good Work
Learning Sacred Knowledge For The Sake Of This World, Or Concealing It
Breach of Trust
Reminding Recipients of Ones Charity To Them
Disbelieving In Destiny (qadar)
Listening To People's Private Conversations
The Talebearer Who Stirs Up Enmity Between People
Breaking Promises or Pledges
Believing Fortune Tellers And Astrologers
Wife Rebelling Against Her Husband