Narrated Anas:

That there was a man who was not very sensible and he would make purchases. So his family came to the Prophet ﷺ and said: "O Messenger of Allah! Stop him (from making purchases)." So Allah's Prophet ﷺ called him to prohibit him, and he said: "O Messenger of Allah! I have no patience for business." So he said: "When you are buying, say: 'Hand to hand, and no cheating.'"

[Abu 'Eisa said:] There is a narration on this topic from Ibn 'Umar.

The Hadith of Anas is a Hasan Sahih Gharib Hadith.

This is acted upon according to the people of knowledge. They say that the free man can be prevented from selling and buying when his intellect is weak. This is the view of Ahmad and Ishaq. Some of the scholars did not think that the free person who had attained the age of responsibility could be prevented from that.

حَدَّثَنَا يُوسُفُ بْنُ حَمَّادٍ الْبَصْرِيُّ، حَدَّثَنَا عَبْدُ الأَعْلَى بْنُ عَبْدِ الأَعْلَى، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، أَنَّ رَجُلاً، كَانَ فِي عُقْدَتِهِ ضَعْفٌ وَكَانَ يُبَايِعُ وَأَنَّ أَهْلَهُ أَتَوُا النَّبِيَّ ﷺ فَقَالُوا يَا رَسُولَ اللَّهِ احْجُرْ عَلَيْهِ . فَدَعَاهُ نَبِيُّ اللَّهِ ﷺ فَنَهَاهُ فَقَالَ يَا رَسُولَ اللَّهِ إِنِّي لاَ أَصْبِرُ عَنِ الْبَيْعِ . فَقَالَ " إِذَا بَايَعْتَ فَقُلْ هَاءَ وَهَاءَ وَلاَ خِلاَبَةَ " .

قَالَ أَبُو عِيسَى وَفِي الْبَابِ عَنِ ابْنِ عُمَرَ . وَحَدِيثُ أَنَسٍ حَدِيثٌ حَسَنٌ صَحِيحٌ غَرِيبٌ . وَالْعَمَلُ عَلَى هَذَا الْحَدِيثِ عِنْدَ بَعْضِ أَهْلِ الْعِلْمِ وَقَالُوا يُحْجَرُ عَلَى الرَّجُلِ الْحُرِّ فِي الْبَيْعِ وَالشِّرَاءِ إِذَا كَانَ ضَعِيفَ الْعَقْلِ . وَهُوَ قَوْلُ أَحْمَدَ وَإِسْحَاقَ . وَلَمْ يَرَ بَعْضُهُمْ أَنْ يُحْجَرَ عَلَى الْحُرِّ الْبَالِغِ .