Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 650
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)