Is it permissible to participate in a charitable project funded by usurious money if it aims to help poor families, and is it permissible for the participants to take profits from their own money, knowing that all remaining usurious money will be spent on the poor?

There is no objection to establishing a project for poor families using funds generated from usurious interest, and there is no objection to participating in it. This is because the prohibition of usurious interest does not extend to the poor who receive it as a means of disposing of it. The money does not become unlawful for them; rather, it is lawful and good.