Narrated `Abdullah bin Abu `Aufa: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)
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.
Bukhari
Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) • Hadith 73