حَدَّثَنَا مُحَمَّدُ بْنُ عِيسَى، حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا عَمْرُو بْنُ دِينَارٍ، عَنْ عَطَاءٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ لَحِقَ الْمُسْلِمُونَ رَجُلاً فِي غُنَيْمَةٍ لَهُ فَقَالَ السَّلاَمُ عَلَيْكُمْ فَقَتَلُوهُ وَأَخَذُوا تِلْكَ الْغُنَيْمَةَ فَنَزَلَتْ ‏{‏ وَلاَ تَقُولُوا لِمَنْ أَلْقَى إِلَيْكُمُ السَّلاَمَ لَسْتَ مُؤْمِنًا تَبْتَغُونَ عَرَضَ الْحَيَاةِ الدُّنْيَا ‏}‏ تِلْكَ الْغُنَيْمَةَ ‏.‏

Narrated Ibn 'Abbas: The Muslims met a man with some sheep of his. He said: Peace be upon you. But they killed him and took those few sheep. Thereupon the following Qur'anic verse was revealed: "...And say to anyone who offers you a salutation: Thou art none of believer, coveting the perishable good of this life." meaning these few sheep. Translation Not Available

Book reference: Sunan Abi Dawud Book 32 Hadith 3974
Web reference: Sunan Abi Dawud Book 31 Hadith 3963