Abu Ishaq said that he heard al-Bara' bin 'Azib (RA) say: The last complete sura revealed (in the Holy Qur'an) is Sura Tauba (i e. al-Bara'at, ix.), and the last verse revealed is that pertaining to Kalala.
Hadith ReferenceSahih Muslim / The Book of the Rules of Inheritance / Hadith: 1618