Sahih al-Bukhari 4551
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · "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 (Paradise)... (till) ... and they shall have a painful torment." (V.3 -77)
Narrated `Abdullah bin Abu `Aufa:
حَدَّثَنَا عَلِيٌّ ـ هُوَ ابْنُ أَبِي هَاشِمٍ ـ سَمِعَ هُشَيْمًا ، أَخْبَرَنَا الْعَوَّامُ بْنُ حَوْشَبٍ ، عَنْ إِبْرَاهِيمَ بْنِ عَبْدِ الرَّحْمَنِ ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي أَوْفَى ـ رضى الله عنهما ـ أَنَّ رَجُلاً، أَقَامَ سِلْعَةً فِي السُّوقِ فَحَلَفَ فِيهَا لَقَدْ أَعْطَى بِهَا مَا لَمْ يُعْطَهُ. لِيُوقِعَ فِيهَا رَجُلاً مِنَ الْمُسْلِمِينَ، فَنَزَلَتْ {إِنَّ الَّذِينَ يَشْتَرُونَ بِعَهْدِ اللَّهِ وَأَيْمَانِهِمْ ثَمَنًا قَلِيلاً} إِلَى آخِرِ الآيَةِ.
A man displayed some merchandise in the market and took an oath that he had been offered a certain price for it while in fact he had not, in order to cheat a man from the Muslims. So then was revealed:-- "Verily! Those who purchase a small gain at the cost of Allah's Covenant and their oaths..."(3.77)