Narrated Al-Qasim bin Abi Bazza: That he asked Sa`id bin Jubair, "Is there any repentance of the one who has murdered a believer intentionally?" Then I recited to him:-- "Nor kill such life as Allah has forbidden except for a just cause." Sa`id said, "I recited this very Verse before Ibn `Abbas as you have recited it before me. Ibn `Abbas said, 'This Verse was revealed in Mecca and it has been abrogated by a Verse in Surat-An-Nisa which was later revealed in Medina."
The chain is ordered from the source of the saying to the compiler: 1 = the speaker/first transmitter, the following links those who passed it on in turn, and at the bottom al-Bukhari who compiled the work. Click a narrator to list every hadith in which he appears; the number in parentheses is how many hadiths across the collections on this site the narrator appears in.