Is it permissible to pay off the debt of a deceased father, and is it true that a debtor will not enter Paradise?

It is permissible and recommended that you assume your father's debts as long as you are able. By assuming them, his responsibility for them is discharged, and they become your responsibility. The sacred texts have indicated the importance of settling the debt of the deceased, and that the soul of a believer is held hostage by his debt until it is paid off. This applies to one who leaves behind wealth from which his debt can be paid. As for one who has no wealth, it is hoped that this hadith does not apply to him.