That the Messenger of Allah (ﷺ) said: "Do not practice An-Najsh." [He said:] There are narrations on this topic from Ibn 'Umar and Anas. [Abu 'Eisa said:] The Hadith of Abu Hurairah is a Hasan Sahih Hadith. This is acted upon according to the people of knowledge, they disliked An-Najsh. [Abu 'Eisa said:] An-Najsh is when a man who knows about the goods comes to the owner of the goods to offer him more than what it is worth, doing so in the presence of the buyer. He intends to seduce the buyer while he himself does not want to buy it, rather he only wants to deceive the buyer with his offer. And this is type of deceit. Ash-Shafi'i said: "If a man commits An-Najsh the he has sinned due to what he has done, but the sale is permissible, because the buyer did not commit An-Najsh."
حَدَّثَنَا قُتَيْبَةُ، وَأَحْمَدُ بْنُ مَنِيعٍ، قَالاَ حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم وَقَالَ قُتَيْبَةُ يَبْلُغُ بِهِ النَّبِيَّ صلى الله عليه وسلم قَالَ لاَ تَنَاجَشُوا . قَالَ وَفِي الْبَابِ عَنِ ابْنِ عُمَرَ وَأَنَسٍ . قَالَ أَبُو عِيسَى حَدِيثُ أَبِي هُرَيْرَةَ حَدِيثٌ حَسَنٌ صَحِيحٌ . وَالْعَمَلُ عَلَى هَذَا عِنْدَ أَهْلِ الْعِلْمِ . كَرِهُوا النَّجْشَ . قَالَ أَبُو عِيسَى وَالنَّجْشُ أَنْ يَأْتِيَ الرَّجُلُ الَّذِي يَفْصِلُ السِّلْعَةَ إِلَى صَاحِبِ السِّلْعَةِ فَيَسْتَامُ بِأَكْثَرَ مِمَّا تَسْوَى وَذَلِكَ عِنْدَمَا يَحْضُرُهُ الْمُشْتَرِي يُرِيدُ أَنْ يَغْتَرَّ الْمُشْتَرِي بِهِ وَلَيْسَ مِنْ رَأْيِهِ الشِّرَاءُ إِنَّمَا يُرِيدُ أَنْ يَخْدَعَ الْمُشْتَرِيَ بِمَا يَسْتَامُ وَهَذَا ضَرْبٌ مِنَ الْخَدِيعَةِ . قَالَ الشَّافِعِيُّ وَإِنْ نَجَشَ رَجُلٌ فَالنَّاجِشُ آثِمٌ فِيمَا يَصْنَعُ وَالْبَيْعُ جَائِزٌ لأَنَّ الْبَائِعَ غَيْرُ النَّاجِشِ .
Tirmizi
The Book on Business • Hadith 1314