If a Musi pays full Hissa Amad on their income without deducting property installment payments, must they still pay full Hissa Jaidad on that property?

Yes. When a person does not have the means to buy a property outright, they acquire a loan to buy it. If they wish to pay Hissa Jaidad on that property during their lifetime, they bear the responsibility for the loan and must pay Hissa Jaidad according to the value of the property at the time of assessment. A loan acquired during one's lifetime is not counted.

The rate of Hissa Jaidad is the rate the Musi chose for themselves, i.e., between 1/10 and 1/3.

Hissa Jaidad is payable at the current market value when the formal assessment is made, except where the Musi already paid Hissa Jaidad on that very property at the time of purchase.