How to expiate the Sin of the Person who indulged in Riba Dealings
Question :
A relative of mine died while he was dealing in Riba and now we want to expiate his sin for him. So, what is the legislated method of doing that?
Answer:
It is legislated for the heirs to seek to find out the amount of the Riba that he took and to give it away in charity on his behalf while also supplicating for forgiveness and pardon for him. We ask Allâh to pardon him, and us and every Muslim.
Source:
Ash-Shaykh Ibn Baz
Fatawa Islamiyah, Vol. 3 Page 360