And the reason behind this is that kufr is of two types: kufr in belief and kufr in action, and the kufr in belief is linked to the heart, and the kufr in action is linked to the limbs.

The reason for the revelation of the verse “the one who does not rule by what Allāh revealed…”, and that it refers to kufr in action not in belief.

2552- Indeed Allāh revealed, “the one who does not rule by what Allāh revealed then they are kāfir”, “they are ẓālim”, “they are fāsiq”. Ibn ʿAbbās said, “Allāh revealed them with regards to two groups from the Jews one of which had overpowered the other to the point that they consented to and agreed that for every person that the victorious tribe (al-ʿAzīza) killed from the subjugated tribe (adh-Dhalīlah) then the ransom was 50 wasq (probably a unit of currency), and that for every person the subjugated tribe killed from the victorious then the ransom was 100 wasq, and they remained in this state until the Prophet (ﷺ) arrived in Madīnah and then both the tribes were subjugated, and that day they did not overcome him because of the peace treaty. Then the subjugated tribe killed a person from the victorious tribe and the victorious tribe sent someone demanding 100 wasq. So the subjugated tribe said: ‘Can this ever be that two people have the same religion, same genealogy, same city and the ransom for some of them be one-half of the others? We only used to give you this ransom due to your injustice to us, and now that Muḥammad has come we will not give you this.’ So a war almost started between them and then they agreed to make the Messenger of Allāh (ﷺ) judge between them. Then the victorious tribe said: ‘by Allāh, Muḥammad will not give you twice the sum of what we gave them for they (the subjugated tribe) spoke the truth, they did not give us this ransom except as an injustice on our part and due to our power over them. So secretly send someone to Muḥammad who can inform you of his opinion, if he gives you what you wish then agree to have him arbitrate, and if he does not then beware and do not agree to have him arbitrate.’ So they sent some people from the hypocrites to Muḥammad. So when the Messenger of Allāh (ﷺ) came, Allāh informed him of all of their affair and what they desired and He, Azza wa Jall, revealed,

يَا أَيُّهَا الرَّسُولُ لَا يَحْزُنكَ الَّذِينَ يُسَارِعُونَ فِي الْكُفْرِ مِنَ الَّذِينَ قَالُوا آمَنَّا بِأَفْوَاهِهِمْ ‎﴿٤١﴾‏ إلى قوله: فَأُولَٰئِكَ هُمُ الْفَاسِقُونَ ‎﴿٤٧﴾‏

“O Messenger! Let not those who hurry into disbelief grieve you, of such who say: ‘we believe’…” to His saying, “then they are fāsiq”
[Al-Māʾidah, 5:41-47].”

Then he (ibn ʿAbbās) said, “By Allāh they were revealed with regards to these two (Jewish tribes), and it was these two that Allāh, Azza wa Jall meant (in these verses)”

Related by Aḥmad (1/246), at-Ṭabarānī in ‘al-Muʿjam al-Kabīr’ (3/95/1) via the route of ʿAbd al-Raḥmān ibn Abī al-Zināʾd from his father from Ubaid Allāh ibn Abd Allāh ibn Utbah ibn Masʿūd from Ibn ʿAbbās that he said: and mentioned the ḥadīth.

And in ‘al-Durar al-Manthūr’ (2/281), al-Ṣuyutī ascribed the ḥadīth to Abū Dāwūd, ibn Jarīr, ibn al-Mundhir, Abū al-Shaykh, ibn Mardawiyyah from ibn ʿAbbās. And it is in the tafsīr of ibn Jarīr (10/352) in this form but he does not mention ibn ʿAbbās in his isnād.

And in Abū Dāwūd (3576) is the (ḥadīth relating to the) revelation of the three verses specifically for the Jews of Qarīdha and an-Nadīr, contravening what may be understood from the saying of ibn Kathīr in his tafsīr (6/160) after reporting this long narration from Aḥmad, “and Abū Dāwūd reports something similar from the ḥadīth of ibn Abī al-Zināʾd from his father.”

And the author of “ar-Rawd al-Bāsim fī adh-Dhabb an al-Sunnah Abī al-Qāsim” quotes from him (ibn Kathīr) that he declared the isnād ḥasan. And I have not seen this in his book ‘al-Tafsīr’ so maybe this occurs in his other works.

And declaring this ḥadīth ḥasan is what the principles of this noble science dictate for it revolves around Abd al-Raḥmān ibn Abī al-Zināʾd and he is as al-Ḥāfiẓ (ibn Hajr) said, “truthful, his memorization changed/failed when he moved to Baghdād, and he was a faqīḥ”

And the saying of al-Haythamī (8/16), “and the likes of it is reported by Aḥmad and at-Ṭabarānī, and in it is Abd al-Raḥmān ibn Abī al-Zināʾd and he is ḍaʿīf, and he has been declared trustworthy, and the remaining narrators of Aḥmad are trustworthy”.

I say: his saying “ḍaʿīf, and he has been declared trustworthy” is not good, because has determined the opinion that he is ḍaʿīf to be stronger than the opinion that he is trustworthy. And the truth is that he is in the middle and that he is ḥasan in ḥadīth except when he contradicts (others), and this cannot be derived from his aforementioned saying. And Allāh knows best.

An important benefit:

When you know that the three verses, “whosoever does nor rule by what Allāh revealed then they are kāfir”, “then they are ẓālim”, and “then they are fāsiq” were revealed with regards to the Jews and their saying over his (ﷺ) judgement, “if he gives you what you want then agree to have him arbitrate, but if does not then beware and do not agree to have him arbitrate” – this saying which the Qurʾān points to before these verses, “they say: if you are given this then take it, but if you are not given this then beware.”- when you understand this then it is not permissible to take these verses to refer to some of the rulers and judges of the Muslims who rule by other than what Allāh revealed in the earthly laws.

I say: it is not permissible to declare them kāfir due to this, and to eject them from the religion, when they are believers in Allāh and His Messenger, even though they are sinning by ruling by other than what Allāh revealed – this is not permissible. Because even though they are like the Jews from the point of view of their ruling (by other than what Allāh revealed), they differ from the point of view that they have faith and conviction in Allāh contradicting the Jews, for indeed they rejected the Messenger (ﷺ) as indicated in their previous saying, “but if he does not then beware and do not agree to have him arbitrate.”

And the reason behind this is that kufr is of two types: kufr in belief and kufr in action, and the kufr in belief is linked to the heart, and the kufr in action is linked to the limbs. So the one whose actions are kufr due to their contradicting the Sharīʿah, and this kufr follows on from what has become established in his heart i.e. kufr in belief, then this is the kufr which Allāh will not forgive and this person will reside in the Fire forever. But if (these kufr actions) contradict what is established in his heart, then he is a believer in the Rule of his Lord, but he contradicts this with his actions. So his kufr is kufr of action only, and it is not kufr in belief. And he is under the Will of Allāh, if He Wills He will punish him, and if He Wills He will forgive him. And it is with this (second) type (of kufr) that some of the aḥādīth are to be understood which generalizes the term kufr for a Muslim who performs a sinful action. And it would be good to mention some:

1. “two things if done are kufr: abusing genealogies and wailing over the dead.” Reported by Muslim
2. “Arguing over the Qurʾān is kufr.”
3. “Abūsing a Muslim is fisq, and killing him is kufr.” Reported by Muslim
4. “Speaking about the favours of Allāh is giving thanks (shukr), and leaving it is kufr”
5. “do not return to being kāfir after me by some of you hitting the necks of (killing) others.” Agreed upon.

And many other aḥādīth for which there is no need to go into great detail at this time. So any Muslim who performs any of these sinful actions, then his kufr is kufr in action i.e. he has done an act of the kuffār. Except in the case that he sees it (the sin) to be permissible, and does not believe in it being a sin, so in this case, he would be a kāfir whose blood is lawful because now he has also shared in the belief of the kuffār.

And a ruling by other than what Allāh revealed is not exempted from this principle, and what is narrated from the salaf supports this, and that is none other than their saying on the tafsīr of this verse, “kufr less than kufr” as is authentically reported from the Commentator of the Qurʾān, ibn ʿAbbās, and then some of the Taabi’een and others learnt this from him. And it is necessary to mention some of them so that maybe they may illuminate the path ahead of those that have been misguided in this dangerous issue, and have taken the road of the Khawārij who declared people to be kāfir due to their committing sins even though they may pray and fast!

1. ibn Jarīr al-Tabarī narrates (10/355/12053) with a ṣaḥīḥ isnād from ibn ʿAbbās that he said about the verse, “whosoever does not rule by what Allāh revealed then they are kāfir”, “meaning kufr, but not kufr in Allāh and His Angels and Books and Messengers”
2. And in a narration from him about this verse, “it is not the kufr that they (i.e. the Khawārij) believe, indeed it is not the kufr that ejects one from the religion, it is kufr less than kufr.”Narrated by al-Ḥākim (2/313) and he said “ṣaḥīḥ isnād” and al-Dhahabī agreed. And it would have been more deserving of them to say, “ṣaḥīḥ according to the conditions of the two Shaykhs (Bukhārī and Muslim)” as the isnād is like this. Then I saw that ibn Kathīr said in his tafsīr (6/163) from Haakim that he said, “ṣaḥīḥ according to the conditions of the two Shaykhs”, so it is obvious that this statement is omitted in the printed edition of ‘al-Mustadrak”. And ibn Kathīr also ascribes the narration, summarised, to ibn Abī Ḥātim.
3. And in another narration from him via the route of ʿAlī ibn Abū Talha from ibn ʿAbbās he said, “the one who rejects what Allāh revealed is a kāfir, and the one who believes in it but does not rule by it is a ẓālim fāsiq.”As reported by ibn Jarīr (12063). I say: ibn Abī Talha did not hear from ibn ʿAbbās, but the narration is good as a witness.
4. Then he (ibn Jarīr) reports (12048-12051) from Ataa ibn Abī Rabaah about the three verses, “kufr less than kufr, fisq less than fisq, ẓulm less than ẓulm.” And it’s isnād is ṣaḥīḥ.
5. Then he reports (12052) from Saʿīd al-Makki from Tawoos about the verse, “it is not the kufr that ejects one from the religion”And it’s isnād is ṣaḥīḥ. And this Saʿīd is ibn Ziyād ash-Shaybaanee al-Makki, and ibn Maʿīn and al-Ijlī and ibn Hibbān and others declared him trustworthy, and a group narrates from him.
6. And he reported (12025, 12026) via two routes of narration from ʿImrān ibn Hadīr who said a group of people from the Banī Umru ibn Sadus [and in another narration: a group from the Ibaadiyyah] came to Abū Mazliz (he is from the great trustworthy tābiʿīn, and his name is Lāhiq ibn Humaid al-Baṣrī) and said: “do you see the saying of Allāh ‘the one who does not rule by what Allāh reveals then they are kāfir’ is this the truth?” He replied, “yes.” They said: ” ‘the one who does not rule by what Allāh revealed then they are ẓālim’ is this the truth?” He replied, “yes.” They said, ” ‘the one who does not rule by what Allāh revealed then they are fāsiq’ is this the truth?” He replied, “yes.” So they said, “O Abū Majliz do these (rulers) rule by what Allāh revealed?” He replied, “this is the religion that they hold to and they call to, so if they leave anything from it they know that they have fallen into sin.” They said, “no by Allāh, but you are afraid and worried.” He said, “you are more deserving of this (description) than me! I do not see this, but you do yet you do not forbid (them from) it. But these verses were revealed with regards to the Jews and Christians and the People of Shirk.” And it’s isnād is ṣaḥīḥ.

And the scholars differed over the explanation of the kufr that is mentioned in the first verse, having five different opinions which ibn Jarīr narrates (10/346-357) with their chains of narration to their proponents. Then he concludes by saying (10/358),

“and the most correct saying of all of these according to me is the saying of the one who says: these verses were revealed with regards to the kuffār of the People of the Book due to the verses before and after them, and they are the people who are meant in them, and the context of these verses is about them. So it is most deserving that the narrative be about them.

So if someone were to say: indeed Allāh generalised the narrative to all who do not rule by what Allāh revealed, so how can you specify it?

It is said (in reply): Indeed Allāh generalized the narrative to all those who reject the Ruling of Allāh that is laid out in His Book. So He informed us about them that they, by their leaving the Ruling – by way of what they left – are kāfir. And this is the saying on all who do not rule by what Allāh revealed, rejecting it – that he is a kāfir as said by ibn ʿAbbās. Because his rejecting the ruling of Allāh after he knows it to have been revealed in His Book is the same as his rejecting the Prophethood of the Prophet after he knows him to be a Prophet.”

In conclusion: the verse was revealed with regards to the Jews who rejected what Allāh had revealed, so the one who associates with them in this rejection, then is a kāfir, with kufr in belief. And the one who does not associate with them in this rejection then his kufr is in action because he has performed an action of theirs. And he is a sinful criminal (mujrim āthim), but he is not ejected from the religion due to this as has preceded ibn ʿAbbās (raḍī Allāhu ʿanhū). And al-Imām Abū Ubaid al-Qāsim ibn Sallām explained this and increased upon this explanation in ‘Kitāb al-Īmān’, chapter “leaving faith due to sin” (pg. 84- 96 with my tahqīq), so the one desiring further research should refer to this.

After writing what has preceded I saw ibn Taymīyyah, may Allāh have mercy upon him, saying in the explanation of the verse in his ‘Majmoo al-Fatāwá’ (3/268), “meaning he regards it permissible to rule by other that what Allāh revealed.”

Then he mentioned (7/254) that Imām Aḥmad was questioned about the kufr mentioned in the verse and he replied, “a kufr which does not eject from faith, like having faith in some of it (?), and likewise with kufr. Until there comes a matter over which there is no difference over.”

And he (ibn Taymīyyah) said (7/312), “so when there is the saying of the salaf that man can have faith and hypocrisy in him, then likewise is their saying that he can have faith and kufr (in him). But not the kufr that ejects one from the religion, as was said by ibn ʿAbbās and his companions over His saying, “the one who does not rule by what Allāh revealed then they are kāfir.” They said: kufr that does not eject one from the religion. And Imām Aḥmad and other Imāms of the Sunnah followed them in this.”

The wording of al-Ṭabarānī has, “And the Messenger of Allāh (ﷺ) did not overcome them or …. On that day as he was in a peace treaty.”

Source: Silsilah al-Ṣaḥihah (vol 6. no.2552) of Shaykh Nāṣir al-Dīn al-Albānī