Ruling on one who sells a product to a person who is buying it with an interest-based loan
Question

                brother if a person is building houses as his job using halal money and sells them to people who are buying them in ribaa, does this person fall into sin. because living in the west it is common knowledge that most people get a loan to buy homes and cannot really afford to buy them cash.
Praise be to Allah.It is better 
    not to get involved with these kinds of transactions, in order to be on the 
    safe side, but the basic principle is that he has nothing to do with the 
    riba-based transaction and he is not a party to it, because the party which 
    is consuming riba is the bank and the one who is paying it is the purchaser 
    of the house.