Sahih al-Bukhari 6744
Narrated Al-Bara:
The last Qur'anic Verse that was revealed (to the Prophet) was the final Verse of Surat-an-Nisa, i.e., 
'They ask you for a legal verdict Say: Allah directs (thus) About those who leave No descendants or 
ascendants as heirs....' (4.176)
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُوسَى، عَنْ إِسْرَائِيلَ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ ـ رضى الله عنه ـ قَالَ آخِرُ آيَةٍ نَزَلَتْ خَاتِمَةُ سُورَةِ النِّسَاءِ ‏{‏يَسْتَفْتُونَكَ قُلِ اللَّهُ يُفْتِيكُمْ فِي الْكَلاَلَةِ‏}‏