What should one do who borrowed an amount from a colleague, then the colleague died, and the borrower discovered that he (the colleague) was an embezzler from his workplace? Should he repay the amount to his family, or to the workplace, or donate it as charity?

The money must be returned to the creditor's heirs after his death, as they are responsible for settling his debts and returning the rights owed by him. If the estate is insufficient to cover all debts, they are entitled to a share proportionate to their inheritance. If the workplace has the right to pardon, it may absolve the deceased of the debt if his heirs request it. The point is that there are possibilities that prevent the questioner's action from being valid in settling his debt by expending it to fulfill a right owed by his deceased debtor. Therefore, he must pay the money to the owner's heirs to clear his conscience.