Regarding the Verse: "And say not to anyone who offers you peace (by accepting Islam), You are not a believer." There was a man amidst his sheep. The Muslims pursued him, and he said (to them) "Peace be on you." But they killed him and took over his sheep. Thereupon Allah revealed in that concern, the above Verse up to:-- "...seeking the perishable good of this life." (4.94) i.e. those sheep.  

السَّلاَمُ عَلَيْكُمْ فَقَتَلُوهُ وَأَخَذُوا غُنَيْمَتَهُ فَأَنْزَلَ اللَّهُ فِي ذَلِكَ إِلَى قَوْلِهِ {عَرَضَ الْحَيَاةِ الدُّنْيَا} تِلْكَ الْغُنَيْمَةُ قَالَ قَرَأَ ابْنُ عَبَّاسٍ السَّلاَمَ  

As-Salam-o-'Alaikum. They caught hold of him and killed him and took possession of his flock. Then this verse was revealed:" He who meets you and extends you salutations, don't say: You are not a Muslim" (iv. 94). Ibn 'Abbas, however, recited the word as-Salam instead of" as-Salam".  

لَقِيَ نَاسٌ مِنَ الْمُسْلِمِينَ رَجُلاً فِي غُنَيْمَةٍ لَهُ فَقَالَ السَّلاَمُ عَلَيْكُمْ فَأَخَذُوهُ فَقَتَلُوهُ وَأَخَذُوا تِلْكَ الْغُنَيْمَةَ فَنَزَلَتْ { وَلاَ تَقُولُوا لِمَنْ أَلْقَى إِلَيْكُمُ السَّلَمَ لَسْتَ مُؤْمِنًا} وَقَرَأَهَا ابْنُ عَبَّاسٍ السَّلاَمَ  

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. (Using translation from Abū Dāʾūd 3974)   

السَّلَامُ عَلَيْكُمْ فَقَتَلُوهُ وَأَخَذُوا غُنَيْمَتَهُ فَأَنْزَلَ اللهُ ﷻ {وَلَا تَقُولُوا لِمَنْ أَلْقَى إِلَيْكُمُ السَّلَامَ لَسْتَ مُؤْمِنًا تَبْتَغُونَ عَرَضَ الْحَيَاةِ الدُّنْيَا} [النساء 94] تِلْكَ الْغُنَيْمَةُ  

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. (Using translation from Abū Dāʾūd 3974)   

السَّلَامُ عَلَيْكُمْ فَقَتَلُوهُ وَأَخَذُوا غَنِيمَتَهُ فَأَنْزَلَ اللهُ تَعَالَى {وَلَا تَقُولُوا لِمَنْ أَلْقَى إِلَيْكُمُ السَّلَامَ لَسْتَ مُؤْمِنًا تَبْتَغُونَ عَرَضَ الْحَيَاةِ الدُّنْيَا} [النساء 94] تِلْكَ الْغَنِيمَةُ