If a Musi has already paid Hissa Jaidad on their house during their lifetime, are the heirs required to pay Hissa Jaidad on the same house after the Musi’s demise?

No. If a Musi paid Hissa Jaidad on their property during their lifetime, the heirs are not required to pay Hissa Jaidad again on that property on behalf of the deceased.

However, once the property is inherited, it becomes the property of the respective heirs. If an heir is a Musi, they are required to pay Hissa Jaidad on their inherited share of the property at their own Wasiyyat rate.