(3) باب آخِرِ آيَةٍ أُنْزِلَتْ آيَةُ الْكَلاَلَةِ
Abu Ishaq said that he heard al-Bara' b. 'Azib (Allah be pleased with him) 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.
Reference: Sahih Muslim 1618 c
In-book reference: Book 23, Hadith 15
USC-MSA web (English) reference(deprecated numbering scheme): Book 11, Hadith 3941