Bukhari

Hadith Commentary:
From the verse of Surah Al-Furqan, it is derived that whoever commits murder but then repents and performs righteous deeds, Allah will accept his repentance. And in the verse of Surah An-Nisa, it is stated that whoever intentionally kills a Muslim will certainly be punished, will remain forever in Hell, and Allah’s wrath and anger will descend upon him.

In this case, there appears to be a contradiction between the contents of the two verses, so Abdur Rahman bin Abza radi Allahu anhu inquired about this matter from Abdullah ibn Abbas radi Allahu anhu, as mentioned here. The intent of Abdullah ibn Abbas radi Allahu anhu was that the verse of Surah Al-Furqan refers to those who, in a state of disbelief, unjustly shed blood, then repent and become Muslim; due to Islam, they will not be held accountable for the unjust bloodshed committed during disbelief. And the verse of Surah An-Nisa pertains to the one who, being a Muslim, intentionally and unjustly kills another Muslim; the punishment for such a person is Hell, and his repentance will not be accepted. Thus, there is no contradiction between the two verses. And the conformity of the hadith with the chapter heading is as follows: it is derived from this that the polytheists unjustly killed Muslims and persecuted them.

Hadith Commentary:
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The relevance of the hadith to the chapter heading is as follows: The polytheists of Makkah said that they had killed such people whose killing Allah had declared unlawful, meaning they themselves admitted that they had inflicted so much torment and suffering upon the Muslims that the Muslims were forced to lose their lives.

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The clarification of the issue mentioned in the hadith is as follows: From the statement of Allah Almighty in Surah Al-Furqan, it is understood that if someone repents after committing unlawful killing and performs righteous deeds, then Allah will accept his repentance ().
Whereas the meaning of the verse from Surah An-Nisa is that whoever intentionally kills a Muslim, his punishment is Hell, wherein he will abide forever ().
Apparently, there is a contradiction between these two verses. The summary of the answer given by Ibn Abbas (radi Allahu anhu) is that the first verse pertains to the disbelievers, and the second verse pertains to the Muslims. Therefore, due to the difference in the circumstances of revelation, there remains no contradiction.
However, this is his personal opinion, which the majority of the Ummah did not accept, nor did his distinguished student, Imam Bukhari (rahimahullah), agree with it.
The position of the majority of Ahl al-Sunnah is that the ruling in Surah An-Nisa is a warning (wa‘id), so that people refrain from killing. However, the repentance of the murderer, like other sins, is also accepted.
We will explain this in detail later.