Will the deceased, who has debts that his heirs are unable to pay, be tormented, and is it permissible for the heirs to recover money owed to him by merchants who deal in prohibited things in order to pay off his debt?

The soul of a believer remains suspended by their debt until it is paid off. This hadith encourages the guardians of the deceased to pay off their debt if they are able. This applies to those who left behind wealth. As for those who have no wealth, it is hoped that the hadith does not apply to them, based on the Almighty's saying: "Allah does not burden a soul beyond its capacity," especially if they incurred debt with the intention of paying it off and did not squander it. If the deceased has wealth, their debt should be paid from it. If they have no wealth and their guardians are able to pay it off, it is a good deed for which they will be rewarded. The money held by merchants belongs to the deceased; their debt should be paid from it, and the remainder goes to their heirs, with the obligation to dispose of any unlawful gains.