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.'"

أَنَّ رَجُلاً ذَكَرَ لِلنَّبِيِّ ﷺ أَنَّهُ يُخْدَعُ فِي الْبُيُوعِ فَقَالَ إِذَا بَايَعْتَ فَقُلْ لاَ خِلاَبَةَ