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 صلى الله عليه وسلم كَانَ يَبْتَاعُ وَفِي عُقْدَتِهِ ضَعْفٌ فَأَتَى أَهْلُهُ نَبِيَّ اللَّهِ صلى الله عليه وسلم فَقَالُوا يَا نَبِيَّ اللَّهِ احْجُرْ عَلَى فُلاَنٍ فَإِنَّهُ يَبْتَاعُ وَفِي عُقْدَتِهِ ضَعْفٌ فَدَعَاهُ النَّبِيُّ صلى الله عليه وسلم فَنَهَاهُ عَنِ الْبَيْعِ فَقَالَ يَا نَبِيَّ اللَّهِ إِنِّي لاَ أَصْبِرُ عَنِ الْبَيْعِ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِنْ كُنْتَ غَيْرَ تَارِكٍ الْبَيْعَ فَقُلْ هَاءَ وَهَاءَ وَلاَ خِلاَبَةَ ‏"‏ ‏.‏ قَالَ أَبُو ثَوْرٍ عَنْ سَعِيدٍ ‏.‏

Narrated Anas ibn Malik: During the time of the Messenger of Allah (PBUH) a man used to buy (goods), and he was weak in his intellect. His people came to the Prophet of Allah (PBUH) 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 (PBUH) 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 (PBUH) said: If you cannot give up making a bargain , then say: Take , and give, and there is no attempt to deceive. Translation Not Available

Book Ref: Sunan Abi Dawud Book 24 Hadith 3501
Web Ref:  Sunan Abi Dawud Book 23 Hadith 3494