I’m curious as to why for a woman, she can’t pray or fast during menses as these are wajib on us, but women are still highly recommended to do mustahhab ‘amal during this time of the month. So like, how come mustahhab actions are actually highly recommended to do,yet the wajibat aren’t allowed?

The wajeb acts like prayer and fasting require spiritual purity, and during the menses, a woman is not ritually pure, so she cannot fulfill the condition of offering them. That’s like praying without Wuhdu—the prayer won’t be valid.

But other recommended acts don’t require purity so she can do them.