Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
حَدَّثَنِي مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا غُنْدَرٌ، حَدَّثَنَا شُعْبَةُ، عَنِ الْمُغِيرَةِ بْنِ النُّعْمَانِ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، قَالَ اخْتَلَفَ أَهْلُ الْكُوفَةِ فِي قَتْلِ الْمُؤْمِنِ، فَرَحَلْتُ فِيهِ إِلَى ابْنِ عَبَّاسٍ، فَقَالَ نَزَلَتْ فِي آخِرِ مَا نَزَلَ وَلَمْ يَنْسَخْهَا شَىْءٌ.Narrated Sa`id bin Jubair:The people of Kufa differed as regards the killing of a believer so I entered upon Ibn `Abbas (and asked him) about that. Ibn `Abbas said, "The Verse (in Surat-An-Nisa', 4:93) was the last thing revealed in this respect and nothing cancelled its validity
From Sahih al-Bukhari, whose reports the scholars accept as authentic.