What is the ruling on money unlawfully mixed with lawful money, in cases where the amount is unknown and it is impossible to return it to its owners, and what is the way to purify it after repentance?

Whoever unlawfully takes another's property is obliged to return it, and his repentance is not complete without doing so. If he does not know the exact amount of the money, he should act based on his best estimate, with caution. If he fears that informing the wronged person would lead to harm, it suffices for him to deliver the money to him by any possible means.

If he is unable to identify the owner of the right or deliver the money to him after searching, he should give the money in charity on his behalf. However, if he later becomes able to reach him, he should offer him the choice between approving the charity or taking his money.