A man displayed some goods in the market and swore by Allah that he had been offered so much for that, that which was not offered, and he said so, so as to cheat a Muslim. On that occasion the following Verse was revealed: "Verily! Those who purchase a small gain at the cost of Allah's covenant and their oaths (They shall have no portion in the Hereafter ..etc.)' (3.77)  

أَنَّ رَجُلاً أَقَامَ سِلْعَةً وَهُوَ فِي السُّوقِ فَحَلَفَ بِاللَّهِ لَقَدْ أَعْطَى بِهَا مَا لَمْ يُعْطَ لِيُوقِعَ فِيهَا رَجُلاً مِنَ الْمُسْلِمِينَ فَنَزَلَتْ {إِنَّ الَّذِينَ يَشْتَرُونَ بِعَهْدِ اللَّهِ وَأَيْمَانِهِمْ ثَمَنًا قَلِيلاً }  

[Machine] A man established a business for himself and he swore by Allah that he had given with it that which he had not given with it. This verse was revealed: "Verily, those who purchase a small gain at the cost of Allah's Covenant and their oaths, they shall have no portion in the Hereafter." (Quran 3:77) The verse says: "And Ibn Abi Awfa Al-Najjashi said: The one who consumes interest is a treacherous eater."  

أَنَّ رَجُلًا أَقَامَ سِلْعَةً لَهُ فَحَلَفَ بِاللهِ لَقَدْ أَعْطَى بِهَا مَا لَمْ يُعْطِ بِهَا فَنَزَلَتْ هَذِهِ الْآيَةُ {إِنَّ الَّذِينَ يَشْتَرُونَ بِعَهْدِ اللهِ وَأَيْمَانِهِمْ ثَمَنًا قَلِيلًا} [آل عمران 77] الْآيَةَ قَالَ وَقَالَ ابْنُ أَبِي أَوْفَى النَّاجِشُ آكِلُ رِبًا خَائِنٌ