6720Sahih BukhariSahihحَدَّثَنَا إِسْمَاعِيلُ، حَدَّثَنَا مَالِكٌ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَجُلاً، ذَكَرَ لِلنَّبِيِّ صلى الله عليه وسلم أَنَّهُ يُخْدَعُ فِي الْبُيُوعِ فَقَالَ إِذَا بَايَعْتَ فَقُلْ لاَ خِلاَبَةَ "Narrated `Abdullah bin `Umar:A man mentioned to the Prophet (ﷺ) that he had always been cheated in bargains. The Prophet (ﷺ) said, "Whenever you do bargain, say, 'No cheating.'"Reference: Sahih al-Bukhari 6964 In-book : Book 90, Hadith 11 USC-MSA web (English) : Vol. 9, Book 86, Hadith 94 (deprecated)