Sahih al-Bukhari 4399
In-book no 4399حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، سَمِعْتُ الْبَرَاءَ ـ رضى الله عنه ـ قَالَ آخِرُ سُورَةٍ نَزَلَتْ بَرَاءَةَ، وَآخِرُ آيَةٍ نَزَلَتْ {يَسْتَفْتُونَكَ }
Narrated Al-Bara: The last Sura that was revealed was Bara'a, and the last Verse that was revealed was: "They ask you for a legal verdict, Say: Allah's directs (thus) about those who leave no descendants or ascendants as heirs." (4.176)