What is the ruling concerning prayers that were performed without ghusl from semen resulting from masturbation, due to ignorance of the obligation of ghusl therefrom?

The ignorance for which one is not excused is ignorance of matters known by necessity to be part of the religion, which are not hidden from the general Muslim populace, and which result from negligence in seeking knowledge and neglecting to ask and research, especially when scholars are available. Ignorance of commanded acts is not excused, unlike ignorance of prohibited acts. Similarly, ignorance of the ruling and its description are both alike. Therefore, prayers performed without proper purification must be made up, along with repentance and an increase in supererogatory acts.