If it is being sold without being sorted or finding out what a consignment contains, it is not permissible to buy it, because that comes under the heading of ambiguity, which is forbidden. This unknown factor renders the transaction invalid, because one of the conditions of a sale being valid is that it be known what is being sold, either by seeing it oneself or by having it described. Secondly: If these clothes are sold after it is known what they are, and the buyer is no longer unaware of what they are, then in principle it is permissible to buy them. Thirdly: If clothing from non-Muslims is washed, there is nothing wrong with using it. Rather the difference of opinion is as to whether it is to be regarded as pure or impure before washing.