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. (Using translation from Abū Dāʾūd 3501)

أَنَّ رَجُلًا عَلَى عَهْدِ رَسُولِ اللَّهِ ﷺ كَانَ يُبَايعُ وَفِي عُقْدَتِهِ ضَعْفٌ فَأَتَى أَهْلُهُ نَبِيَّ اللَّهِ ﷺ فَقَالُوا يَا نَبِيَّ اللَّهِ احْجُرْ عَلَى فُلَانٍ فَإِنَّهُ يُبَايعُ وَفِي عُقْدَتِهِ ضَعْفٌ فَدَعَاهُ نَبِيُّ اللَّهِ ﷺ فَنَهَاهُ عَنِ الْبَيْعِ فَقَالَ يَا نَبِيَّ اللَّهِ لَا أَصْبِرْ عَنِ الْبَيْعِ فَقَالَ نَبِيُّ اللَّهِ «إِنْ كُنْتَ غَيْرَ تَارِكٍ لِلْبَيْعِ فَقُلْ هَاءً وَهَاءً وَلَا خِلَابَةَ»