What is the ruling on a menstruating woman entering the mosque to attend religious lessons and learn the Qur'an, knowing that the reason for prohibiting entry is the fear of defiling the mosque, and there is no such fear today, and that most of the hadiths mentioned regarding the prohibition of entry do not reach the degree of a good (hasan) hadith?

It is impermissible for a menstruating woman to remain in the mosque, even for the purpose of learning or teaching the Quran. This is the view of the majority of scholars, who cite as evidence the Almighty's saying: "Nor as those who are impure [junub], until you have bathed, except when passing through [a mosque while traversing]." Menstruation is similar to ritual impurity (janaba) and exceeds it in that it is a harm (adha). They also cite as evidence the narration from Aisha, may Allah be pleased with her: "Indeed, I do not permit the mosque for a menstruating woman nor for one who is impure," and the Prophet's (peace be upon him) saying to Aisha when he told her: "Hand me the prayer mat from the mosque," and she said: "I am menstruating," to which he replied: "Verily, your menstruation is not in your hand." The reason a menstruating woman is forbidden from entering the mosque is because she is menstruating, and the wisdom behind this prohibition is the fear that she might soil the mosque. Rulings are tied to their causes, not to their underlying wisdom.