Answered by Shaykh Amjad Rasheed
Is it permitted to accept a gift from someone whose money is mixed with the unlawful?
Yes it is permitted to do so. The gift would be considered lawful property. However, taking such a gift is disliked- as our Imams stated- unless the taker knows that that gift comes from unlawful money such as a stolen article or one which was sold through an invalid dealing such as usury.
The author of al-Tuhfa said that Imam Nawawi narrated and acknowledged the words of Imam Abu Hamid al-Ghazali in al-Majmu`. Imam Ghazali said, “it is offensive to take from someone whose money is divided into halal and haram such as the money of an unjust ruler. Although offensiveness vary in accordance to the degree of one’s doubt, it is not unlawful to take something unless one is certain that it comes from unlawful money.”
Imam Nawawi also state in his al-Majmoo, “al-Ghazali was alone in his opinion that it is unlawful to take from or deal with someone whose unlawful money is greater than his lawful money. That is to say al- Ghazali in his al-Baseet followed the way of scrupulousness (war) and gave the fatwa that it is unlawful to deal with someone whose money mostly comes from usury. However, it is not unlawful even if one is most likely to believe that the money comes from usury. That is because the relied-upon proof of ownership is having something under one’s hand. In the absence of proof to the contrary, strong doubts are of no consequence.”
– Amjad
(Translated by Abu Muhammad Rahil)