From Sahih Bukhari (Hadith 4763):
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
Reference: Bukhari 4763