Sahih al-Bukhari, Volume 5, Book 59, Hadith 650 (USC-MSA) ⓘ

Narrated Al-Bara: The last Sura which was revealed in full was Baraa (i.e. Sura-at-Tauba), and the last Sura (i.e. part of a Sura) which was revealed was the last Verses of Sura-an-Nisa':-- "They ask you for a legal decision. Say: Allah directs (thus) About those who have No descendants or ascendants As heirs." (4.177)

حَدَّثَنِي عَبْدُ اللَّهِ بْنُ رَجَاءٍ، حَدَّثَنَا إِسْرَائِيلُ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ ـ رضى الله عنه ـ قَالَ آخِرُ سُورَةٍ نَزَلَتْ كَامِلَةً بَرَاءَةٌ، وَآخِرُ سُورَةٍ نَزَلَتْ خَاتِمَةُ سُورَةِ النِّسَاءِ ‏{‏يَسْتَفْتُونَكَ قُلِ اللَّهُ يُفْتِيكُمْ فِي الْكَلاَلَةِ‏}‏