Was the questioner excused for his ignorance regarding the obligation to wash between the buttocks when performing ghusl for janabah?

The entire body must be covered with water during ghusl al-janabah (ritual bath after sexual impurity), including the area between the buttocks. Failure to wash this area after knowing its obligation is considered a sin and invalidates the prayer. As for what passed before gaining this knowledge, there is no sin for someone who is new to Islam or grew up in an environment where ignorance is widespread. However, for someone whose circumstances do not justify such ignorance, they are negligent and sinful. All prayers performed with this incomplete ghusl must be made up, regardless of whether one was ignorant or not.