Almighty Allah has made giving advice and demonstrating transparency obligatory in religion in general and in transactions in particular.
The Islamic Law (Sharee’ah) also opposes all forms of manipulative and deceptive acts and practices. [See ‘Abd Ar-Rahmaan Al-Hamadhaanee, Al-Alfaadh Al-Kitaabiyah, pp. 175 and 278.]
In fact, in fighting such forms of deception, Islam has not confined itself to giving advice and guidance; rather, it has established certain rulings which range from prohibition, to punishment to discretionary correction.
It commands its followers to observe truthfulness, honesty and tolerance when dealing with others.
The Prophet (صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ) once said,
“May Allah’s mercy be on him who is lenient in his buying, selling, and in demanding back his money.” Reported by Al-Bukhaaree, Book of Sales, 4/384, on the authority of Jaabir ibn ‘Abdullaah (may Allah be pleased with him).
He صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ also said,
The trustworthy and honest trader will be in the company of the prophets, the truthful and the martyrs.” Reported by At-Tirmidhee in Al-Jaami’, Book of Sales, 3/515, hadeeth no. 1209; and Ad-Daarimee in As-Sunan, Book of Sales, 2/322, hadeeth no. 2539. The chain of narration of this report is categorized as ‘weak’ due to the ‘interruption’ in the chain at Al-Hasan Al-Basree who did not really hear it from Abu Sa’eed Al-Khudree. Both Ibn Al-Madeenee and Ad-Daarimee are of this opinion. Commenting on this hadeeth, Ad-Daarimee writes, “I do not believe that Al-Hasan heard it from Abu Sa’eed.” See Tahdheeb At-Tahdheeb, 1/389. At-Tirmidhee (Book of Sales, 3/515-516) reports a relatively similar hadeeth which he classifies as being ‘authentic’.
The Islam also considers lying, especially when used to unjustly take the property of a Muslim, one of the seven great destructive sins. [This refers to the hadeeth reported by Al-Bukhaaree and Muslim in which the Prophet (صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ) said, “Avoid the seven great destructive sins.” The people enquired, “What are they, Messenger of Allah?” “He صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ said, “To join others in worship along with Allah, to practise sorcery, to kill the life which Allah has forbidden except for a just cause (i.e. according to Islamic law), to eat up riba (usury), to eat up an orphan’s wealth, to give back to the enemy and to flee from the battlefield at the time of fighting, and to accuse, chaste women, who never even think of anything touching chastity and are good believers.” See Al-Bukhaaree, Book of Wills and Testaments; Fath Al-Baaree, 5/494, hadeeth no. 2766; and Muslim, Book of Faith, 1/92, hadeeth no. 89. The hadeeth was narrated on the authority of Abu Hurayrah (may Allah be pleased with him).]
To emphasize the wickedness of deception, the Qur’an mentions the word ghuroor (deception) and its derivatives 28 times, the word khiyaanah (treachery, deception) and its derivatives 16 times and the word khid’ah (fraud, delusion, deception) 5 times. See The Principle of Satisfaction in Concluding Contracts (in Arabic), 1/667
Islam strictly forbids such deceptive practices and evidence to this effect comes from the Qur’an, the Prophetic traditions as well as the unanimous agreement of Muslim scholars, as follows: