Using unlawful earnings to pay for marriage expenses
4-12-2013 | IslamWeb
Question:
salam my question is that me and my wife work in supermarket and sometimes we have to scan pork or wine, now we are saving up money using our salaries to try and get my brother married. will his marraige be valid if we fund it knowing that our earning has some haram in it
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
It is not permissible for a Muslim to help sell what is forbidden, like alcohol and pork, in his work, and the money gained from that is forbidden. There is a severe threat for those who aid in the consumption of alcohol. Ibn ‘Umar 
said: “The Prophet said: "Allaah has cursed wine, its drinker, its server, its seller, its buyer, its presser, the one who demands it to be pressed, its carrier and the one to whom it is carried." [Abu Daawood - Al-Albaani graded it Saheeh (sound)]
However, if you pay the marriage expenses of your brother with this ill-gotten money, his marriage is valid if it fulfills the conditions of a valid marriage contract even if you paid his dowry from your forbidden earnings. In fact, the marriage contract is valid even if the dowry itself is unlawful. Ibn Qudaamah 
said: “If an unlawful dowry was named in the marriage contract, like alcohol or pig, then the dowry is invalid but the marriage contract is valid. Ahmad was cited as saying so and it is the opinion of the majority of Fiqh scholars, including Ath-Thawri, Al-Awzaa’i, Ash-Shaafi’i, and the scholars of the Hanafi school."
On the other hand, you are liable for the money that you and your wife have earned unlawfully, and if this money is transferred to your brother through gift or any other permissible method, the money becomes lawful for him. Shaykh Ibn ‘Uthaymeen said: “The invitation of a person who deals in Riba (usurious interest) may be accepted unless there is a benefit in not honoring such an invitation. The evidence for this is that the Prophet accepted the invitation of Jews while the Prophet was the most pious and God-fearing person, and it is known that the Jews take Riba and consume forbidden money; nevertheless, he responded to some of their invitations. This is because unlawful money is considered unlawful only for the person who earned it by a forbidden means, unless the property is in itself unlawful; as in this case, it is also forbidden for others. This is the rule supported by evidence. 'In itself unlawful' means for instance that a person stole someone else's property and then gives it as a gift to someone else. It is not permissible for the receiver of the gift to accept it if he knows that it was stolen, because the money is in itself unlawful, contrary to the money that is unlawfully earned (like the money earned from Riba or selling unlawful goods). This is because the sin in the latter case lies on the one who earns it. If the forbidden property is transferred to someone else by lawful means, it is lawful to the latter.”
Allaah Knows best.