رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1582
The Book of the Prohibited actions
Prohibition of Deceiving others
وعنه قَالَ: ذَكَرَ رَجُلٌ لِرَسُولِ اللَّهِ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ أَنَّهُ يُخْدَعُ فِي الْبُيُوعِ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ: "مَنْ بَايَعْتَ؟ فَقُلْ : لاَ خِلاَبَةَ" ((مُتَّفَقٌ عَلَيْهِ)). "الخِلابة" بخاء معجمة مكسورة، وباء موحدة: وهي الخديعة.
Ibn 'Umar (May Allah be pleased with them) said: A man mentioned to the Messenger of Allah (ﷺ) that he was often deceived in dealings. The Messenger of Allah (ﷺ) said to him, "When you enter into a transaction you should say: "There should be no deception."' [Al-Bukhari and Muslim].
Riyad as-Salihin, 1582