Example of an issue: A Muslim sells one dirham to a harbi (non-Muslim at war with Muslims) while both are in the land of war, on the condition that the Muslim takes two dirhams from him, and the sale is immediate.
Condition of the issue: The increase must be for the Muslim. If the increase is for the disbeliever, then it is unanimously impermissible. The author of al-Muheet al-Burhani said: If he buys from them one dirham for two dirhams, it is not allowed by agreement, because that would be helping them by the value of the extra dirham, and showing kindness to them through that (al-Muheet al-Burhani fi al-Fiqh al-Nu‘mani 7/232, see also al-Asl by al-Shaybani 3/71, al-Bahr al-Ra’iq Sharh Kanz al-Daqa’iq, and Ibn Abidin’s commentary Minhat al-Khaliq 6/147).
The scholars differed on this issue into three opinions:
The first opinion: That it is permissible and there is no harm in it.
This was the view of Abu Hanifah, Muhammad ibn al-Hasan (see al-Mabsut 14/56, al-Muheet al-Burhani 7/231, al-Bahr al-Ra’iq 6/147, Ibn Abidin’s Hashiyah 5/186), and Ibrahim al-Nakha‘i (see Mukhtasar Ikhtilaf al-‘Ulama 3/491).
The second opinion: That it is permissible for a Muslim to engage in Riba with a Harbi, as long as the Muslim is not a person of safety (musta’man) in the land of war.
This is a narration from Imam Ahmad, chosen by al-Majd ibn Taymiyyah (see al-Insaf 12/135, al-Muharrar fi Madhhab al-Imam Ahmad 1/318).
Ibn Taymiyyah the grandson said it was explicitly stated by the Imam (see al-Furu‘ with Tashih al-Furu‘ 6/292, Bada’i‘ al-Fawa’id 4/214, al-Mubdi‘ Sharh al-Muqni‘ 4/153).
The third opinion: That it is absolutely forbidden.
This was the view of Abu Yusuf and al-Sarakhsi among the Hanafis (see al-Radd ‘ala Siyar al-Awza‘i p. 97, al-Mabsut 14/57)
The Malikis (see al-Mudawwanah 3/294–295, al-Mukhtasar al-Fiqhi by Ibn ‘Arafah 5/209, al-Tabsirah by al-Khami 6/2801, al-Qawanin al-Fiqhiyyah p. 486),
The Shafi‘is (see Rawdat al-Talibin 3/397 and 10/291, Asna al-Matalib 2/22),

Translation: Riba is prohibited equally for the man and the woman, the slave and the mukatab (a slave who has entered into a contract with their master to purchase their freedom by paying a specific sum of money over a set period) by consensus.
There is no distinction in its prohibition between Dar al-Islam and Dar al-Harb. Whatever is haram in Dar al-Islam remains haram in Dar al-Harb, whether it takes place between Muslims or between a Muslim and a harbi, whether the Muslim enters that land with aman (a covenant of safety) or without it. This is our madhhab, and it is also the position of Malik, Ahmad, Abu Yusuf, and the majority of the fuqaha.
Abu Hanifah held that riba is not haram in Dar al-Harb between a Muslim and the ahl al-harb, nor between Muslims who have not made hijrah from there. So if a Muslim sells to a harbi in Dar al-Harb one dirham for two dirhams, or if two Muslims there who have not made hijrah exchange one dirham for two, it is permissible.
He used as proof what was narrated from Mak’hul from the Prophet ﷺ: “There is no riba between a Muslim and a harbi in Dar al-Harb.” He also argued that the wealth of the ahl al-harb is mubah (permissible to take) without a contract, so through a fasid (invalid) contract it is even more so.
An Nawawi’s companions responded by referring to the general texts of the Quran and Sunnah that forbid riba without differentiation, and because what is riba in Dar al-Islam is riba in Dar al-Harb and is haram there as well, just as if two Muslims who had made hijrah engaged in it, or a Muslim and a harbi traded in Dar al-Islam. Also, whatever is haram in Dar al-Islam is haram in Dar al-Harb, like khamr and other maʿasi (acts of disobedience). Furthermore, it is a contract upon something invalid in Dar al-Islam, so it remains invalid there, like a batil nikah (void marriage).
As for the hadith of Mak’hul, it is mursal and daʿif (weak), so it is not a valid proof. And if it were authentic, the answer would be that its meaning is interpreted to be that riba is not made halal in Dar al-Harb, in order to reconcile it with the other proofs.
As for their claim that the wealth of the harbi is permissible without a contract, this assertion is not accepted if the Muslim enters their land with aman (a covenant of safety). And if he enters it without aman, then the reasoning is flawed, just as when a harbi enters Dar al-Islam and a Muslim sells to him one dirham for two dirhams.
Moreover, the fact that their wealth can be taken through ghanimah (spoils of war) does not mean it is permissible to take it through a fasid (invalid) contract. For this reason, their women may be taken as captives through saby (captivity in jihad), but not through an invalid marriage contract.
Al-Majmu’ Sharh al-Muhaddhab By An-Nawawi (9/488-489)
The Hanbalis according to the correct view in the madhhab (see al-Insaf 12/135, Sharh al-Muntaha 2/79).
It was also the view of Ishaq and al-Awza‘i (see al-Mughni by Ibn Qudamah 6/98-99).

Translation: Riba is prohibited in the land of war just as it is prohibited in the land of Islam
Riba is forbidden in the land of war, just as it is forbidden in the land of Islam. This was the view of Malik, al-Awza‘i, Abu Yusuf, al-Shafi‘i, and Ishaq.
Abu Hanifah said: Riba does not apply between a Muslim and a harbi (a non-Muslim at war with Muslims) in the land of war. It is also narrated from him that if two Muslims embrace Islam in the land of war, there is no riba between them.
This is based on what Mak‘hul narrated from the Prophet (peace and blessings be upon him), that he said: There is no riba between Muslims and the people of war in the land of war (see: footnote 26). They also said: Their wealth is originally permissible, and only becomes protected due to the safety agreements (aman) in the land of Islam. So, if there is no such protection, it remains permissible.
Our evidence: The saying of Allah, the Most High: And Allah has forbidden riba (al-Baqarah: 275).
And His saying: Those who consume riba will not stand except as one whom Satan has driven to madness (al-Baqarah: 275).
And His saying: O you who believe, fear Allah and give up what remains of riba (al-Baqarah: 278).
The general wording of these reports requires the prohibition of any excess in exchange. The Prophet, also said: Whoever increases or takes an increase has committed riba. This is general, and so are all the other hadiths.
Also, whatever is forbidden in the land of Islam remains forbidden in the land of war, such as riba between Muslims. As for their strongest evidence, it is a mursal report whose authenticity is unknown. It may also be understood as a prohibition rather than a negation. It is not allowed to abandon what the Quran clearly prohibits, what the Sunnah has repeatedly affirmed, and what the consensus of the ummah has agreed upon, in favour of a report that is unknown, not mentioned in any authentic collection, not connected through a sound chain, and not found in any reliable book. It is, in addition, a mursal narration that is open to interpretation.
It may also be that the intended meaning of the statement there is no riba is in fact a prohibition of riba, just like in the verse: There is to be no sexual relations, sin, or disputing during Hajj (al-Baqarah: 197).
As for what they claimed regarding permissibility, it is contradicted by the case of the harbi who enters the land of Islam, for his wealth is not completely lawful, except in what the aman excludes. This issue may also be interpreted in a way where the exchange takes place between Muslims in a form of inequality, which is unanimously prohibited. So the same ruling applies here as well.
Al-Mughni by Ibn Qudamah (6/98-99)
Evidence of the first opinion:
First evidence: What was reported from Mak‘hul that the Messenger of Allah (peace and blessings be upon him) said: There is no riba between Muslims and the people of war in the land of war (mentioned by Abu Yusuf in al-Radd ‘ala Siyar al-Awza‘i p. 97.)
It is disconnected and without an isnad. (Also mentioned by al-Sarakhsi in al-Mabsut 14/56, al-Nawawi in al-Majmu‘ 9/392, Ibn Qudamah in al-Mughni 4/32).
Evidence: The Prophet (peace and blessings be upon him) negated riba between Muslims and people of war in their land, which shows it is allowed if the transaction takes place in their territory (see al-Mabsut 14/56, al-Binayah Sharh al-Hidayah 8/299).
This was refuted in two ways:
First: The hadith is weak, has no known origin, and none of the major scholars of Islam mentioned it. Al-‘Ayni the Hanafi said: This hadith is strange and has no established chain (al-Binayah Sharh al-Hidayah 8/299).
Imam Ash-Shafi‘i said: It is not authentic, so it is not a valid proof (al-Umm 7/379). Even if accepted as having some origin, it is mursal and cannot oppose the general evidences prohibiting riba (see al-Silsilah al-Da‘ifah 14/79. Also weakened by al-Zayla‘i in Nasb al-Rayah 4/44, and al-Nawawi in al-Majmu‘ 9/392).
Second: If we assume the hadith is valid, it can be understood that the word “la” is a prohibition, not a negation. This reconciles the evidences and avoids contradiction (see al-Hawi al-Kabir 5/75, al-Majmu‘ 9/392, al-Mughni 4/33).
Second evidence: From Ibn ‘Abbas (may Allah be pleased with him) regarding the verse: Alif Lam Meem. The Romans have been defeated (al-Rum: 1–2). He said: They were defeated and then they defeated others. The polytheists liked the Persians to win because they were idol worshippers, and the Muslims liked the Romans to win because they were People of the Book. They mentioned this to Abu Bakr who told the Prophet (peace and blessings be upon him). He said: They will be victorious.
So Abu Bakr said to the Quraysh: Let us agree on a term. If we win, you give us such and such. If you win, we give you such and such. They set a term of five years, but the Romans did not win. Abu Bakr informed the Prophet (peace and blessings be upon him), and he said: Why did you not make it less than ten? Sa‘id ibn Jubayr said: Bidh‘ means less than ten.
Then the Romans were victorious. That is the meaning of Allah’s saying… and on that day the believers will rejoice with the help of Allah (Reported by al-Tirmidhi in his Sunan, Book of Tafsir, chapter on Surah al-Rum, hadith 3193. He said: This is a hasan gharib hadith. Ibn al-Qayyim also graded it sahih in al-Furusiyyah al-Muhammadiyyah p. 145, and said its chain is authentic and it was authenticated by al-Tirmidhi and others).
Evidence: This was a form of gambling, which is generally prohibited, yet the Prophet (peace and blessings be upon him) approved it for Abu Bakr, indicating it is allowed with disbelievers. They were in Makkah, which was a land of war (see al-Mabsut 14/57).
Refuted in two ways:
First: This ruling was abrogated. It occurred before gambling was prohibited. This is evident from some versions of the hadith (reported by al-Tirmidhi 3194, 5/197).
Second: This is not the type of gambling that is forbidden. Riba is only prohibited when it leads to unlawful consumption of wealth. But what serves to strengthen Islam and its proof is not considered gambling (see al-Furusiyyah al-Muhammadiyyah p. 23).
Third evidence: The Prophet (peace and blessings be upon him) wrestled Rukanah for a sheep and defeated him (reported by Abu Dawud in al-Marasil 308, p. 235, from ‘Amr ibn Dinar from Sa‘id ibn Jubayr. Al-Albani in Irwa’ al-Ghalil 5/330 said al-Khatib al-Baghdadi connected it through a sound chain, and concluded the isnad is at least hasan. Ibn al-Qayyim praised some of its routes in al-Furusiyyah p. 140, and quoted Ibn Taymiyyah saying: The story is well known among scholars).
Evidence: The Prophet (peace and blessings be upon him) accepted the sheep from Rukanah, and only returned it as a favour. There was no third party to make the wager valid, yet he still took it. This shows such a deal is permissible between a Muslim and a harbi in the land of war (see al-Mabsut 14/57).
Refuted: This is not prohibited gambling. In fact, it is permitted and aligned with legal principles, as explained by many scholars. Whoever claims it is prohibited or that there is a difference between the wealth of a disbeliever and others must bring proof (see al-Furusiyyah al-Muhammadiyyah p. 141).
Fourth evidence: The Prophet (peace and blessings be upon him) said during the Farewell Pilgrimage: The riba of the pre-Islamic period is abolished, and the first riba I abolish is our riba, the riba of al-‘Abbas ibn ‘Abd al-Muttalib (reported by Muslim in his Sahih, Book of Hajj, chapter on the Hajj of the Prophet, hadith 1218, 2/886, from the hadith of Jabir ibn ‘Abdullah).
Evidence: His saying The riba of Jahiliyyah is abolished indicates that riba was still being practised until the conquest of Makkah. His saying The first riba I abolish is that of al-‘Abbas means that it was still ongoing up until that time, although he had accepted Islam earlier (see al-Mu‘tasar from Mukhtasar Mushkil al-Athar 1/342, Sharh Mushkil al-Athar 8/247, al-Mabsut 14/57).
Refuted: This is not a sound proof. First, the Farewell Pilgrimage occurred after the conquest of Makkah, and many people had accepted Islam. So the one using this hadith as evidence must prove that the riba of al-‘Abbas was with disbelievers.
Second, even if it was, the hadith supports the opinion that riba is forbidden. The Prophet (peace and blessings be upon him) invalidated riba between a Muslim and disbelievers in a situation that originated when Makkah was still a land of war (see al-Asl by al-Shaybani 3/74).
Fifth evidence from reasoning: The wealth of the harbi is lawful for the Muslim. Riba was only prohibited because it is consuming wealth unjustly, and that does not apply with someone whose wealth is not protected. A treaty of safety does not make wealth protected, it only prevents betrayal. If they agree to the transaction, then it is allowed (see al-Hidayah Sharh Bidayat al-Mubtadi 3/66, al-Bahr al-Ra’iq 6/147).
Refuted: This meaning is not accepted, because it equates entering their land with or without safety. This logic applies even in the land of Islam. So what is the difference between the two situations? (see al-Majmu‘ 9/392, al-Mughni 4/33)
Evidence of the second opinion:
They use some of the previous evidences. But their specific reasoning is that the wealth of a harbi is not protected. So if the Muslim gains it in any way, it is lawful. Therefore, it is permissible for a Muslim to take wealth from a harbi through riba. The difference is that the wealth of a person of safety is protected, while the harbi’s is not (see al-Mubdi‘ Sharh al-Muqni‘ 4/153).
Refuted in three ways:
First: The verses forbidding riba are general and not restricted. The most clear of them is: Allah has permitted trade and forbidden riba (al-Baqarah: 275), and the Prophet (peace and blessings be upon him) cursed both the consumer and giver of riba (reported by al-Bukhari in his Sahih, Book of Clothing, chapter on those who curse image-makers, hadith 5962, 7/169, from Abu Juhaifah).
Second: This is an analogy against a clear text, so it is invalid (see al-Sharh al-Mumti‘ 8/456).
Third: Not everything that is allowed without a contract is allowed through a corrupt one. For example, women can be taken as captives through lawful war, not through invalid marriage contracts. The same applies to wealth (see al-Hawi al-Kabir 5/75).
Evidence of the third opinion:
First: The general proofs prohibiting riba, such as Allah’s saying: Those who consume riba will not stand except like one touched by Satan. That is because they say: Trade is like riba. But Allah has permitted trade and forbidden riba (al-Baqarah: 275), and His saying: O you who believe, fear Allah and leave what remains of riba (al-Baqarah: 278) (see al-Majmu‘ 9/392, al-Sharh al-Kabir ‘ala al-Muqni‘ 12/136).
Second: The reason for prohibition in this case is the extra amount in exchanging dirhams, and that is present in dealings with a harbi. The ruling follows its cause wherever it exists. There is no proof to restrict it to Muslims or protected disbelievers (see al-Mumti‘ 2/504).
Third: From reasoning: Whatever is haram in the land of Islam remains haram in the land of war, like alcohol and other immoralities (see al-Hawi al-Kabir 5/75).
Preferred view:
The third view which prohibits riba absolutely is best, because the evidences used are general and unrestricted, and the other views do not answer them with valid evidence. Their strongest arguments are weak analogies or unauthentic hadiths that do not oppose the clear authentic texts.
Reason for the disagreement:
It appears the disagreement goes back to two matters:
First: Whether disbelievers are addressed with the detailed rulings of Sharia. Those who said they are not, allowed the contract in this form. This was mentioned by al-Zamakhshari in Ru’us al-Masa’il p. 282.
However, this is questionable, because the permissibility mentioned by those who allow it is based on the increase being for the Muslim, not the other way around. So the issue is not whether the disbeliever is accountable, but whether it is lawful for the Muslim.
Second: The disagreement over the authenticity of the hadith of Mak‘hul and how it should be understood, and likewise the analogy regarding the permissibility of harbi wealth and whether it can be extended to corrupt contracts.
