Narrated Anas ibn Malik:

During the time of the Messenger of Allah ﷺ a man used to buy (goods), and he was weak in his intellect. His people came to the Prophet of Allah ﷺ and said: Prophet of Allah, stop so-and-so (to make a bargain) for he buys (goods), but he is weak in his intellect. So the Prophet ﷺ called on him and forbade him to make a bargain. He said: Prophet of Allah, I cannot keep away myself from business transactions. Thereupon the Messenger of Allah ﷺ said: If you cannot give up making a bargain , then say: Take , and give, and there is no attempt to deceive.

حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الأَرُزِّيُّ، وَإِبْرَاهِيمُ بْنُ خَالِدٍ أَبُو ثَوْرٍ الْكَلْبِيُّ، - الْمَعْنَى - قَالاَ حَدَّثَنَا عَبْدُ الْوَهَّابِ، - قَالَ مُحَمَّدٌ عَبْدُ الْوَهَّابِ بْنُ عَطَاءٍ - أَخْبَرَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ رَجُلاً، عَلَى عَهْدِ رَسُولِ اللَّهِ ﷺ كَانَ يَبْتَاعُ وَفِي عُقْدَتِهِ ضَعْفٌ فَأَتَى أَهْلُهُ نَبِيَّ اللَّهِ ﷺ فَقَالُوا يَا نَبِيَّ اللَّهِ احْجُرْ عَلَى فُلاَنٍ فَإِنَّهُ يَبْتَاعُ وَفِي عُقْدَتِهِ ضَعْفٌ فَدَعَاهُ النَّبِيُّ ﷺ فَنَهَاهُ عَنِ الْبَيْعِ فَقَالَ يَا نَبِيَّ اللَّهِ إِنِّي لاَ أَصْبِرُ عَنِ الْبَيْعِ . فَقَالَ رَسُولُ اللَّهِ ﷺ " إِنْ كُنْتَ غَيْرَ تَارِكٍ الْبَيْعَ فَقُلْ هَاءَ وَهَاءَ وَلاَ خِلاَبَةَ " . قَالَ أَبُو ثَوْرٍ عَنْ سَعِيدٍ .