No one is unaware of the fact that stealing is a major sin, for which Allaah has enjoined the punishment of having the hand cut off. Sharee’ah makes no distinction between the wealth of a male and the wealth of a female, or between the wealth of a minor and the wealth of an adult, or between the wealth of a Muslim and the wealth of a kaafir. The only exception made by sharee’ah is the wealth of kaafirs who are waging war against the Muslims. 

The Muslim should be a good example of trustworthiness, honouring agreements and good character. When Muslims have had such characteristics, this has been the cause of many kaafirs entering Islam, because they saw the beauties of Islam and the good character of its people. 

The Muslim who regards the kaafirs’ wealth as permissible, whether he is in a Muslim country or in a kaafir country, is doing the kaafirs a great favour and helping them to distort the image of Islam and Muslims; he is thereby helping those who are launching attacks against Islam. 

When a Muslim enters a kaafir country, it is as if he entering into a peaceful agreement with them – which is the visa which is given to him to enable him to enter their country – so if he takes their wealth unlawfully, then he is breaking that agreement, in addition to being a thief. 

The wealth that he steals from them is haraam. It was narrated that al-Mugheerah ibn Shu’bah kept company with some people during the Jaahiliyyah. He killed them and took their wealth, then he came and entered Islam. The Prophet (peace and blessings of Allaah be upon him) said: “As for your Islam, I accept it, and as for the wealth, I have nothing to do with it.” According to a report narrated by Abu Dawood, “As for your Islam, we accept it, and as for the wealth it is obtained through treachery, and we have no need of it.”

(Narrated by al-Bukhaari, 2583; Abu Dawood, 2765; classed as saheeh by al-Albaani in Saheeh Abi Dawood, 2403).

Al-Haafiz Ibn Hajar said: 

The phrase “and as for the wealth, I have nothing to do with it” means, I will not touch it because it was obtained through treachery. What we learn from this is that it is not permissible to take the wealth of the kuffaar by treachery when they have trusted you and granted you safety, because when people accompany one another (when travelling), they do so on the basis of mutual trust, and that trust should not be betrayed, whether the other person is a Muslim or a kaafir. The wealth of the kuffaar is only permissible in the case of combat and war. Perhaps the Prophet (peace and blessings of Allaah be upon him) let him keep the wealth in the hope that the people of its owner might become Muslim, then he could return their wealth to them. 

Fath al-Baari, 5/341 

Al-Shaafa’i (may Allaah have mercy on him) said: When a Muslim enters dar al-harb (the non-Muslim lands) on peaceful terms, and finds himself in position to take something of their wealth, it is not permissible for him to take it, whether it is a little or a lot, because if he is safe from them, they should be safe from him, and because it is not permissible for him to take anything from them when they have given him safety except what it is permissible for him to take from the wealth of the Muslims and ahl al-dhimmah (non-Muslims living under the protection of the Muslim state). Wealth may be forbidden for a number of reasons:

If the owner is a Muslim

if the owner is (a non-Muslim) living under the protection of the Muslim state

if the owner is one with whom there is a peace deal, until the deal expires; such people are considered to be like ahl al-dhimmah as far as the sanctity of their wealth is concerned, until the deal expires. 

Al-Umm, 4/284 

Al-Sarkhasi (may Allaah have mercy on him) said: It is not right for a Muslim who is on peaceful terms with them to betray them, because betrayal is haraam. The Prophet (peace and blessings of Allaah be upon him) said: “Every betrayer will have a banner by his backside on the Day of Resurrection, by which his betrayal will be known.” If he betrays them and steals their wealth, and brings it to the Muslim lands, it is not right for a Muslim to buy from him if he knows about that, because he has obtained it in an evil manner, and buying from him is encouraging him in that, which it is not right for the Muslim to do. The basic principle in this matter is the hadeeth of al-Mugheerah ibn Shu’bah (may Allaah be pleased with him), when he killed his companions and brought their wealth to Madeenah and became Muslim, and asked the Messenger of Allaah (peace and blessings of Allaah be upon him) to take the khums of his wealth, and he said, “As for your Islam, we accept it, and as for the wealth it is obtained through treachery, and we have no need of it.” 

Al-Mabsoot, 10/96 

And Allaah knows best.