(66) باب حَجُّ أَبِي بَكْرٍ بِالنَّاسِ فِي سَنَةِ تِسْعٍ
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)
Reference: Sahih al-Bukhari 4364
In-book reference: Book 64, Hadith 390
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 5, Book 59, Hadith 650