What is forbidden mixing, and what is the ruling on attending mixed lessons, with evidence, and is it permissible to attend them if most of the students are women and some of them are non-Muslims?

Mixing between men and women is forbidden in Islamic law because it causes temptation and arouses desires, leading to indecencies. This is supported by Quranic verses and Prophetic traditions, including the Almighty's saying: "And when you ask [his wives] for anything, ask them from behind a partition. That is purer for your hearts and their hearts." The Sunnah of the Prophet also took into account the prohibition of mixing even in mosques, by separating the rows of women from men, and the Prophet, peace and blessings be upon him, would remain after the taslim until the women had left, and by designating a special door for women in the mosque. Studies have shown that the majority of Muslim society does not permit mixing and prefers to work in non-mixed environments, and that mixing leads to social and moral problems.