“The verse, ‘And whoever deliberately kills a believer...,’ was revealed, and we became apprehensive because of it. Then the verse in Surat al-Furqan was revealed: ‘And those who do not call upon any deity besides Allah...’—the rest of the verse.” This is a rejected narration. I do not know who made the error, for al-Nasa’i reports it, as does Abu Dawud, through a single chain: Muslim ibn Ibrahim narrated to us; Hammad ibn Salamah narrated to us, from Abd al-Rahman ibn Ishaq, with it. Were it not for this, it would be clear that the error lay with Majalid ibn Awf, given what you know of his being an unknown narrator. And Allah knows best.
Second: In the aforementioned narration of al-Bukhari from Ibn Abbas, he said: “There is no repentance for one who kills deliberately.” This is well-known from him and has many chains, as Ibn Kathir and Ibn Hajar stated. The majority hold the contrary view, which is unquestionably correct. The verse in Surat al-Furqan is explicit on this point, and the verse in Surat al-Nisa’ does not contradict it, for the latter concerns the killer’s punishment, not his repentance. This is very clear. It seems that Ibn Abbas retracted to this view, as I have found in some reports from him. I considered it necessary to mention them because of their scarcity and because the two hadith authorities omitted them.
The first is what Ata ibn Yasar narrated from him: A man came to him and said, “I proposed to a woman, but she refused to marry me. Another man proposed to her, and she wished to marry him. I became jealous over her and killed her. Is there any repentance for me?” He asked, “Is your mother alive?” The man said, “No.” He said: “Repent to Allah and draw near to Him as much as you can.”
I then went and asked Ibn Abbas, “Why did you ask him whether his mother was alive?” He replied: “I know of no deed that brings one nearer to Allah than dutifulness to one’s mother.” Al-Bukhari recorded it in al-Adab al-Mufrad (no. 4) with an authentic chain meeting the criteria of the two Sahih collections.