I asked Ibn Abbas, and he said, "When the verse in al-Furqan was revealed, 'And those who do not invoke another god alongside Allah, nor kill the soul which Allah has forbidden except by right' [Furqan 25:68], the polytheists of Mecca said, 'We have killed the soul which Allah has forbidden, we have invoked another god alongside Allah, and we have committed indecencies.' So Allah revealed, 'Except for those who repent, believe, and do righteous deeds, for them Allah will replace their evil deeds with good ones' [Furqan 25:70]. This applies to those people."He continued, "As for the verse in an-Nisa, 'Whoever kills a believer intentionally, his recompense is Hell' [Nisa 4:93], this means that when a man has come to know the laws of Islam and then kills a believer intentionally, his recompense is Hell, with no repentance available to him."I mentioned this to Mujahid, and he said, "Except for the one who feels remorse."
حدثنا يوسف بن موسى حدثنا جرير عن منصور عن سعيد بن جبير أو حدثني الحكم
سألت ابن عباس فقال لما نزلت التي في الفرقان {والذين لا يدعون مع الله إلها آخر ولا يقتلون النفس التي حرم الله إلا بالحق} قال مشركو أهل مكة قد قتلنا النفس التي حرم الله ودعونا مع الله إلها آخر وأتينا الفواحش فأنزل الله {إلا من تاب وآمن وعمل عملا صالحا فأولئك يبدل الله سيئاتهم حسنات} فهذه لأولئك قال وأما التي في النساء {ومن يقتل مؤمنا متعمدا فجزاؤه جهنم} الآية قال الرجل إذا عرف شرائع الإسلام ثم قتل مؤمنا متعمدا فجزاؤه جهنم لا توبة له فذكرت هذا لمجاهد فقال إلا من ندم
Bukhari transmitted it in the Book of the Virtues of the Ansar, chapter on what the Prophet ﷺ and his companions suffered from the polytheists in Makkah, hadith no. 3855, from the hadith of Jareer, and Muslim transmitted it in the Book of tafsir, chapter before, chapter 1, hadith no. 3023, from the hadith of Mansoor, with the same wording.