حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ - وَاللَّفْظُ لاِبْنِ الْمُثَنَّى - قَالاَ حَدَّثَنَا مُحَمَّدُ، بْنُ جَعْفَرٍ حَدَّثَنَا شُعْبَةُ، عَنْ سِمَاكِ بْنِ حَرْبٍ، عَنْ مُصْعَبِ بْنِ سَعْدٍ، عَنْ أَبِيهِ، قَالَ نَزَلَتْ فِيَّ أَرْبَعُ آيَاتٍ أَصَبْتُ سَيْفًا فَأَتَى بِهِ النَّبِيَّ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ نَفِّلْنِيهِ ‏.‏ فَقَالَ ‏"‏ ضَعْهُ ‏"‏ ‏.‏ ثُمَّ قَامَ فَقَالَ لَهُ النَّبِيُّ صلى الله عليه وسلم ‏"‏ ضَعْهُ مِنْ حَيْثُ أَخَذْتَهُ ‏"‏ ‏.‏ ثُمَّ قَامَ فَقَالَ نَفِّلْنِيهِ يَا رَسُولَ اللَّهِ ‏.‏ فَقَالَ ‏"‏ ضَعْهُ ‏"‏ ‏.‏ فَقَامَ فَقَالَ يَا رَسُولَ اللَّهِ نَفِّلْنِيهِ أَأُجْعَلُ كَمَنْ لاَ غَنَاءَ لَهُ فَقَالَ لَهُ النَّبِيُّ صلى الله عليه وسلم ‏"‏ ضَعْهُ مِنْ حَيْثُ أَخَذْتَهَ ‏"‏ ‏.‏ قَالَ فَنَزَلَتْ هَذِهِ الآيَةُ ‏{‏ يَسْأَلُونَكَ عَنِ الأَنْفَالِ قُلِ الأَنْفَالُ لِلَّهِ وَالرَّسُولِ‏}‏

A hadith has been narrated by Mus'ab b. Sa'd who heard it from his father as saying: " Four verses of the Qur'an have been revealed about me. I found a sword (among the spoils of war). It was brought to the Prophet (PBUH). He (my father) said: Messenger of Allah, bestow it upon me. The Apostle of Allah (PBUH) said: Place it there. Then he (my father) stood up and the Messenger of Allah (PBUH) said to him: Place it from where you got it. (At this) he (my father) said again: Messenger of Allah, bestow it upon me Shall I be treated like one who has no share in (the booty)? The Apostle of Allah (may peace be upon him said: Place it from where you got it. At this was revealed the verse:" They ask thee about the spoils of war.... Say: The spoils of war are for Allah and the Messenger" Translation Not Available

Book reference: Sahih Muslim Book 32 Hadith 4329
Web reference: Sahih Muslim Book 19 Hadith 1748 b